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Publications of year 2005

Books and proceedings

  1. Ian G. Cumming and Frank H. Wong. Digital Processing of Synthetic Aperture Radar Data: Algorithms and Implementation. Artech House Inc., Boston, London, 2005. Keyword(s): SAR Processing, Range-Doppler Algorithm, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm, Range Migration Algorithm, omega-k, Wavenumber Domain Algorithm, SPECAN Algorithm, Comparison of Algorithms, Demodulation, Quadrature Demodulation, Hilbert Transform, Doppler Centroid Estimation, Doppler Ambiguity Resolver, DAR, Doppler Rate Estimation, Azimuth FM Rate, Autofocus Techniques, ScanSAR, Range Compression, Pulse Compression, Pulse Compression of Linear FM Signals, Linear FM Signals, Stolt Mapping, Quality Assessment, Quality Measures, Quality Metrics, PSLR, ISLR, Spaceborne SAR.
    Abstract: This cutting-edge resource offers you complete howto guidance on digital processing of synthetic aperture radar (SAR) data. You discover how SAR is used to obtain a high-resolution image from a satellite and learn the mathematical structure and spectral properties of the signal received from a SAR system. Supported with over 600 equations and over 250 figures, the book arms you with state-of-the-art signal processing algorithms and helps you choose the best algorithm for a given SAR system and image quality requirements. This hands-on reference shows you how to process received SAR data into a well-focused image on a digital computer, using the popular range Doppler, chirp scaling, omega-K and SPECAN algorithms. In addition, the book teaches you how to process ScanSAR data using the full-aperture, SPECAN, short IFFT and extended chirp scaling algorithms. You also learn how to estimate the Doppler centroid frequency and azimuth FM rate from a geometry model or from received data. Written from a digital signal processing point of view, this authoritative volume can be fully understood by professionals with a general electrical engineering background.

    @Book{cummingWong05:SARBook,
    Title = {Digital Processing of Synthetic Aperture Radar Data: Algorithms and Implementation},
    Author = {Ian G. Cumming and Frank H. Wong},
    Publisher = {Artech House Inc.},
    Url = {http://www.artechhouse.com},
    Year = {2005},
    Abstract = {This cutting-edge resource offers you complete howto guidance on digital processing of synthetic aperture radar (SAR) data. You discover how SAR is used to obtain a high-resolution image from a satellite and learn the mathematical structure and spectral properties of the signal received from a SAR system. Supported with over 600 equations and over 250 figures, the book arms you with state-of-the-art signal processing algorithms and helps you choose the best algorithm for a given SAR system and image quality requirements. This hands-on reference shows you how to process received SAR data into a well-focused image on a digital computer, using the popular range Doppler, chirp scaling, omega-K and SPECAN algorithms. In addition, the book teaches you how to process ScanSAR data using the full-aperture, SPECAN, short IFFT and extended chirp scaling algorithms. You also learn how to estimate the Doppler centroid frequency and azimuth FM rate from a geometry model or from received data. Written from a digital signal processing point of view, this authoritative volume can be fully understood by professionals with a general electrical engineering background.},
    Address = {Boston, London},
    Keywords = {SAR Processing, Range-Doppler Algorithm, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm,Range Migration Algorithm, omega-k, Wavenumber Domain Algorithm, SPECAN Algorithm, Comparison of Algorithms, Demodulation, Quadrature Demodulation, Hilbert Transform, Doppler Centroid Estimation, Doppler Ambiguity Resolver, DAR, Doppler Rate Estimation, Azimuth FM Rate, Autofocus Techniques, ScanSAR, Range Compression, Pulse Compression, Pulse Compression of Linear FM Signals, Linear FM Signals,Stolt Mapping, Quality Assessment,Quality Measures,Quality Metrics,PSLR, ISLR,Spaceborne SAR},
    Owner = {ofrey} 
    }
    


  2. Petre Stoica and Randolph L. Moses. Spectral Analysis of Signals. Prentice Hall, Upper Saddle River, NJ, 2005. Keyword(s): Spectral Estimation, MUSIC, Capon, Beamforming, Direction-of-arrival estimation, SAR Processing, SAR Tomography.
    @Book{stoicaMosesBook2005:SpectralAnalysis,
    Title = {Spectral Analysis of Signals},
    Author = {Petre Stoica and Randolph L. Moses},
    Publisher = {Prentice Hall},
    Url = {http://www.ece.osu.edu/~randy/SAtext},
    Year = {2005},
    Address = {Upper Saddle River, NJ},
    Keywords = {Spectral Estimation,MUSIC, Capon, Beamforming, Direction-of-arrival estimation, SAR Processing, SAR Tomography},
    Owner = {ofrey} 
    }
    


Articles in journal or book chapters

  1. Richard Bamler and Michael Eineder. Accuracy of differential shift estimation by correlation and split-bandwidth interferometry for wideband and delta-k SAR systems. IEEE Geoscience and Remote Sensing Letters, 2(2):151-155, April 2005. Keyword(s): SAR Processing, split-bandwidth, geophysical signal processing, image registration, radar imaging, radar interference, remote sensing by radar, speckle, synthetic aperture radar, Cramer-Rao bound, Delta-k interferometry, clutter, coherent speckle correlation, differential delay estimation, differential shift estimation, digital elevation model, ground motion mapping, image coregistration, image correlation, incoherent speckle correlation, macro-scale shift estimation, phase cycle ambiguities, phase unwrapping, point scatterers, speckle tracking, split-bandwidth interferometry, synthetic aperture radar, Bandwidth, Clutter, Digital elevation models, Equations, Interferometry, Motion estimation, Radar scattering, Speckle, Synthetic aperture radar, Wideband, Cramer-Rao bound (CRB), Delta-k interferometry, differential delay estimation, image correlation, speckle tracking, split-bandwidth interferometry, synthetic aperture radar (SAR) image coregistration.
    Abstract: Estimation of differential shift of image elements between two synthetic aperture radar (SAR) images is the basis for many applications, like digital elevation model generation or ground motion mapping. The shift measurement can be done nonambiguously on the macro scale at an accuracy depending on the range resolution of the system or on the micro scale by employing interferometric methods. The latter suffers from phase cycle ambiguities and requires phase unwrapping. Modern wideband high-resolution SAR systems boast resolutions as small as a few tens of a wavelength. If sufficiently many samples are used for macro-scale shift estimation, the accuracy can be increased to a small fraction of a resolution cell and even in the order of a wavelength. Then, accurate absolute ranging becomes precise enough to support phase unwrapping or even make it obsolete. This letter establishes a few fundamental equations on the accuracy bounds of shift estimation accuracy for several algorithms: coherent speckle correlation, incoherent speckle correlation, split-band interferometry, a multifrequency approach, and correlation of point scatterers in clutter. It is shown that the performance of split-band interferometry is close to the Cramer-Rao bound for a broad variety of bandwidth ratios. Based on these findings, Delta-k systems are proposed to best take advantage of the available radar bandwidth.

    @Article{bamlerEinederGRSL2005,
    author = {Richard Bamler and Michael Eineder},
    title = {Accuracy of differential shift estimation by correlation and split-bandwidth interferometry for wideband and delta-k SAR systems},
    journal = {IEEE Geoscience and Remote Sensing Letters},
    year = {2005},
    volume = {2},
    number = {2},
    pages = {151-155},
    month = apr,
    issn = {1545-598X},
    abstract = {Estimation of differential shift of image elements between two synthetic aperture radar (SAR) images is the basis for many applications, like digital elevation model generation or ground motion mapping. The shift measurement can be done nonambiguously on the macro scale at an accuracy depending on the range resolution of the system or on the micro scale by employing interferometric methods. The latter suffers from phase cycle ambiguities and requires phase unwrapping. Modern wideband high-resolution SAR systems boast resolutions as small as a few tens of a wavelength. If sufficiently many samples are used for macro-scale shift estimation, the accuracy can be increased to a small fraction of a resolution cell and even in the order of a wavelength. Then, accurate absolute ranging becomes precise enough to support phase unwrapping or even make it obsolete. This letter establishes a few fundamental equations on the accuracy bounds of shift estimation accuracy for several algorithms: coherent speckle correlation, incoherent speckle correlation, split-band interferometry, a multifrequency approach, and correlation of point scatterers in clutter. It is shown that the performance of split-band interferometry is close to the Cramer-Rao bound for a broad variety of bandwidth ratios. Based on these findings, Delta-k systems are proposed to best take advantage of the available radar bandwidth.},
    doi = {10.1109/LGRS.2004.843203},
    file = {:bamlerEinederGRSL2005.pdf:PDF},
    keywords = {SAR Processing, split-bandwidth,geophysical signal processing;image registration;radar imaging;radar interference;remote sensing by radar;speckle;synthetic aperture radar;Cramer-Rao bound;Delta-k interferometry;clutter;coherent speckle correlation;differential delay estimation;differential shift estimation;digital elevation model;ground motion mapping;image coregistration;image correlation;incoherent speckle correlation;macro-scale shift estimation;phase cycle ambiguities;phase unwrapping;point scatterers;speckle tracking;split-bandwidth interferometry;synthetic aperture radar;Bandwidth;Clutter;Digital elevation models;Equations;Interferometry;Motion estimation;Radar scattering;Speckle;Synthetic aperture radar;Wideband;Cramer-Rao bound (CRB);Delta-k interferometry;differential delay estimation;image correlation;speckle tracking;split-bandwidth interferometry;synthetic aperture radar (SAR) image coregistration},
    owner = {ofrey},
    pdf = {../../../docs/bamlerEinederGRSL2005.pdf},
    
    }
    


  2. Federica Bordoni, Fabrizio Lombardini, Fulvio Gini, and A. Jakobsson. Multibaseline cross-track SAR interferometry using interpolated arrays. IEEE Transactions on Aerospace and Electronic Systems, 41(4):1473-1482, 2005. Keyword(s): SAR Processing, SAR Tomography, Tomography, Layover, Array Interpolation.
    Abstract: This work deals with the problem of interferometric radar phase estimation in the presence of layover. The focus here is on multichannel interferometric synthetic aperture radar (InSAR) systems with a low number of phase centers and nonuniform array geometry. An interpolated array (IA) approach is proposed in order to apply parametric spectral estimation techniques designed for uniform linear arrays (ULAs). In particular, the interpolated MUSIC and weighted subspace fitting (WSF) algorithms are considered and compared with conventional methods. Performance analysis under different InSAR scenarios is carried out based on Monte Carlo simulations. The Cramer-Rao lower bound (CRLB) for the nonuniform interferometric array is derived and reported as a benchmark on the estimation accuracy.

    @Article{bordoniLombardiniGiniJakobsson05:Tomo,
    Title = {Multibaseline cross-track SAR interferometry using interpolated arrays},
    Author = {Bordoni, Federica and Lombardini, Fabrizio and Gini, Fulvio and Jakobsson, A.},
    ISSN = {0018-9251},
    Number = {4},
    Pages = {1473--1482},
    Url = {http://ieeexplore.ieee.org/iel5/7/33161/01561898.pdf},
    Volume = {41},
    Year = {2005},
    Abstract = {This work deals with the problem of interferometric radar phase estimation in the presence of layover. The focus here is on multichannel interferometric synthetic aperture radar (InSAR) systems with a low number of phase centers and nonuniform array geometry. An interpolated array (IA) approach is proposed in order to apply parametric spectral estimation techniques designed for uniform linear arrays (ULAs). In particular, the interpolated MUSIC and weighted subspace fitting (WSF) algorithms are considered and compared with conventional methods. Performance analysis under different InSAR scenarios is carried out based on Monte Carlo simulations. The Cramer-Rao lower bound (CRLB) for the nonuniform interferometric array is derived and reported as a benchmark on the estimation accuracy.},
    Journal = {IEEE Transactions on Aerospace and Electronic Systems},
    Keywords = {SAR Processing, SAR Tomography, Tomography, Layover, Array Interpolation},
    Owner = {ofrey},
    Pdf = {../../../docs/bordoniLombardiniGiniJakobssonTomo05.pdf} 
    }
    


  3. E.J. Candes and T. Tao. Decoding by linear programming. IEEE Transactions on Information Theory, 51(12):4203-4215, December 2005. Keyword(s): Gaussian random matrix, basis pursuit, linear code decoding, linear programming, minimization problem, natural error correcting problem, simple convex optimization problem, sparse solution, uncertainty principle, Gaussian processes, convex programming, decoding, error correction codes, indeterminancy, linear codes, linear programming, minimisation, random codes, sparse matrices;.
    Abstract: This paper considers a natural error correcting problem with real valued input/output. We wish to recover an input vector f isin;Rn from corrupted measurements y=Af+e. Here, A is an m by n (coding) matrix and e is an arbitrary and unknown vector of errors. Is it possible to recover f exactly from the data y? We prove that under suitable conditions on the coding matrix A, the input f is the unique solution to the #8467;1-minimization problem (||x|| #8467;1:= Sigma;i|xi|) min(g isin;Rn) ||y - Ag|| #8467;1 provided that the support of the vector of errors is not too large, ||e|| #8467;0:=|{i:ei ne; 0}| le; rho; middot;m for some rho;>0. In short, f can be recovered exactly by solving a simple convex optimization problem (which one can recast as a linear program). In addition, numerical experiments suggest that this recovery procedure works unreasonably well; f is recovered exactly even in situations where a significant fraction of the output is corrupted. This work is related to the problem of finding sparse solutions to vastly underdetermined systems of linear equations. There are also significant connections with the problem of recovering signals from highly incomplete measurements. In fact, the results introduced in this paper improve on our earlier work. Finally, underlying the success of #8467;1 is a crucial property we call the uniform uncertainty principle that we shall describe in detail.

    @Article{1542412,
    Title = {Decoding by linear programming},
    Author = {Candes, E.J. and Tao, T.},
    Doi = {10.1109/TIT.2005.858979},
    ISSN = {0018-9448},
    Month = dec,
    Number = {12},
    Pages = {4203-4215},
    Volume = {51},
    Year = {2005},
    Abstract = {This paper considers a natural error correcting problem with real valued input/output. We wish to recover an input vector f isin;Rn from corrupted measurements y=Af+e. Here, A is an m by n (coding) matrix and e is an arbitrary and unknown vector of errors. Is it possible to recover f exactly from the data y? We prove that under suitable conditions on the coding matrix A, the input f is the unique solution to the #8467;1-minimization problem (||x|| #8467;1:= Sigma;i|xi|) min(g isin;Rn) ||y - Ag|| #8467;1 provided that the support of the vector of errors is not too large, ||e|| #8467;0:=|{i:ei ne; 0}| le; rho; middot;m for some rho;>0. In short, f can be recovered exactly by solving a simple convex optimization problem (which one can recast as a linear program). In addition, numerical experiments suggest that this recovery procedure works unreasonably well; f is recovered exactly even in situations where a significant fraction of the output is corrupted. This work is related to the problem of finding sparse solutions to vastly underdetermined systems of linear equations. There are also significant connections with the problem of recovering signals from highly incomplete measurements. In fact, the results introduced in this paper improve on our earlier work. Finally, underlying the success of #8467;1 is a crucial property we call the uniform uncertainty principle that we shall describe in detail.},
    Journal = {IEEE Transactions on Information Theory},
    Keywords = {Gaussian random matrix; basis pursuit; linear code decoding; linear programming; minimization problem; natural error correcting problem; simple convex optimization problem; sparse solution; uncertainty principle; Gaussian processes; convex programming; decoding; error correction codes; indeterminancy; linear codes; linear programming; minimisation; random codes; sparse matrices;} 
    }
    


  4. Karlus A. Câmara de Macedo and Rolf Scheiber. Precise topography- and aperture-dependent motion compensation for airborne SAR. IEEE Geosci. Remote Sens. Lett., 2(2):172-176, 2005. Keyword(s): SAR Processing, PTA-MoComp, Postprocessing, Motion Compensation, Topography-Based Motion Compensation, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm, fast Fourier transform-based postprocessing methodology, FFT, D-InSAR, German Aerospace Center, DLR, airborne repeat-pass interferometry, differential interferometry, geometric fidelity, motion errors, phase accuracy, residual phase errors, topographic heights, Topography, DEM, Terrain, wide beamwidth, Airborne SAR, ESAR, P-Band, differential interferometry, Interferometry, motion errors.
    Abstract: Efficient synthetic aperture radar (SAR) processing algorithms are unable to exactly implement the aperture- and topography-dependent motion compensation due to the superposition of the synthetic apertures of several targets having different motion errors and potentially different topographic heights. Thus, during motion compensation, a reference level is assumed, resulting in residual phase errors that impact the focusing, geometric fidelity, and phase accuracy of the processed SAR images. This letter proposes a new short fast Fourier transform-based postprocessing methodology capable of efficient and precise compensation of these topography- and aperture-dependent residual phase errors. In addition to wide beamwidth (very high resolution) SAR systems, airborne repeat-pass interferometry especially benefits from this approach, as motion compensation can be significantly improved, especially in areas with high topographic changes. Repeat-pass interferometric data of the E-SAR system of the German Aerospace Center (DLR) are used to demonstrate the performance of the proposed approach.

    @Article{deMacedoScheiber05:DEMBasedMoComp,
    Title = {{Precise topography- and aperture-dependent motion compensation for airborne SAR}},
    Author = {C{\^a}mara de Macedo, Karlus A. and Scheiber, Rolf},
    Number = {2},
    Pages = {172-176},
    Url = {http://ieeexplore.ieee.org/iel5/8859/30687/01420299.pdf},
    Volume = {2},
    Year = {2005},
    Abstract = {Efficient synthetic aperture radar (SAR) processing algorithms are unable to exactly implement the aperture- and topography-dependent motion compensation due to the superposition of the synthetic apertures of several targets having different motion errors and potentially different topographic heights. Thus, during motion compensation, a reference level is assumed, resulting in residual phase errors that impact the focusing, geometric fidelity, and phase accuracy of the processed SAR images. This letter proposes a new short fast Fourier transform-based postprocessing methodology capable of efficient and precise compensation of these topography- and aperture-dependent residual phase errors. In addition to wide beamwidth (very high resolution) SAR systems, airborne repeat-pass interferometry especially benefits from this approach, as motion compensation can be significantly improved, especially in areas with high topographic changes. Repeat-pass interferometric data of the E-SAR system of the German Aerospace Center (DLR) are used to demonstrate the performance of the proposed approach.},
    Journal = {IEEE Geosci. Remote Sens. Lett.},
    Keywords = {SAR Processing, PTA-MoComp, Postprocessing, Motion Compensation, Topography-Based Motion Compensation, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm, fast Fourier transform-based postprocessing methodology,FFT, D-InSAR, German Aerospace Center, DLR, airborne repeat-pass interferometry, differential interferometry, geometric fidelity, motion errors, phase accuracy, residual phase errors, topographic heights, Topography,DEM,Terrain, wide beamwidth, Airborne SAR, ESAR, P-Band, differential interferometry, Interferometry, motion errors},
    Owner = {ofrey},
    Pdf = {../../../docs/deMacedoScheiber05.pdf} 
    }
    


  5. M. Eineder and N. Adam. A maximum-likelihood estimator to simultaneously unwrap, geocode, and fuse SAR interferograms from different viewing geometries into one digital elevation model. Geoscience and Remote Sensing, IEEE Transactions on, 43(1):24 - 36, jan. 2005. Keyword(s): SAR interferogram fusion, SAR interferogram geocoding, SAR interferogram unwrapping, SRTM, Shuttle Radar Topography Mission, critical phase-unwrapping, digital elevation model, geometric baseline error estimates, heterogeneous synthetic aperture radar interferograms, incidence angle, interferometric multiangle observations, interferometric multibaseline observations, map geometry, maximum-likelihood algorithm, maximum-likelihood estimation, periodic likelihood function, radar baseline, radar heading angle, radar wavelength, rugged terrain, scatterer height, terrain mapping, viewing geometries, geophysical signal processing, maximum likelihood estimation, radar signal processing, radiowave interferometry, remote sensing by radar, synthetic aperture radar, terrain mapping;.
    Abstract: This paper presents theory, algorithm, and results of a maximum-likelihood algorithm that is capable to fuse a number of heterogeneous synthetic aperture radar interferograms into a single digital elevation model (DEM) without the need for the critical phase-unwrapping step. The fusion process takes place in the object space, i.e., the map geometry, and considers the periodic likelihood function of each individual interferometric phase sample. The interferograms may vary regarding their radar wavelength, their baseline, their heading angle (ascending or descending), and their incidence angle. Geometric baseline error estimates and a priori knowledge from other estimates like existing DEMs are incorporated seamlessly into the estimation process. The presented approach significantly differs from the standard DEM generation method where each interferogram is first phase-unwrapped individually, then geocoded into a common map geometry, and finally averaged with DEMs generated from other interferograms. By avoiding the phase-unwrapping step, the proposed algorithm does not depend on gradients between samples and is therefore capable to reconstruct the arbitrary height of each single scatterer. Because the height of each DEM sample is determined individually, spatial propagation of phase-unwrapping errors is avoided. The algorithm is targeted to fuse an ensemble of interferometric multiangle or multibaseline observations in areas of rugged terrain or highly ambiguous data where algorithms based on phase unwrapping may fail. The algorithm is explained, and examples with real data from the Shuttle Radar Topography Mission are given. Conditions of future missions are simulated, and optimization criteria for the viewing geometry are discussed.

    @Article{1381616,
    author = {Eineder, M. and Adam, N.},
    journal = {Geoscience and Remote Sensing, IEEE Transactions on},
    title = {A maximum-likelihood estimator to simultaneously unwrap, geocode, and fuse SAR interferograms from different viewing geometries into one digital elevation model},
    year = {2005},
    issn = {0196-2892},
    month = {jan.},
    number = {1},
    pages = {24 - 36},
    volume = {43},
    abstract = {This paper presents theory, algorithm, and results of a maximum-likelihood algorithm that is capable to fuse a number of heterogeneous synthetic aperture radar interferograms into a single digital elevation model (DEM) without the need for the critical phase-unwrapping step. The fusion process takes place in the object space, i.e., the map geometry, and considers the periodic likelihood function of each individual interferometric phase sample. The interferograms may vary regarding their radar wavelength, their baseline, their heading angle (ascending or descending), and their incidence angle. Geometric baseline error estimates and a priori knowledge from other estimates like existing DEMs are incorporated seamlessly into the estimation process. The presented approach significantly differs from the standard DEM generation method where each interferogram is first phase-unwrapped individually, then geocoded into a common map geometry, and finally averaged with DEMs generated from other interferograms. By avoiding the phase-unwrapping step, the proposed algorithm does not depend on gradients between samples and is therefore capable to reconstruct the arbitrary height of each single scatterer. Because the height of each DEM sample is determined individually, spatial propagation of phase-unwrapping errors is avoided. The algorithm is targeted to fuse an ensemble of interferometric multiangle or multibaseline observations in areas of rugged terrain or highly ambiguous data where algorithms based on phase unwrapping may fail. The algorithm is explained, and examples with real data from the Shuttle Radar Topography Mission are given. Conditions of future missions are simulated, and optimization criteria for the viewing geometry are discussed.},
    doi = {10.1109/TGRS.2004.838389},
    keywords = {SAR interferogram fusion; SAR interferogram geocoding; SAR interferogram unwrapping; SRTM; Shuttle Radar Topography Mission; critical phase-unwrapping; digital elevation model; geometric baseline error estimates; heterogeneous synthetic aperture radar interferograms; incidence angle; interferometric multiangle observations; interferometric multibaseline observations; map geometry; maximum-likelihood algorithm; maximum-likelihood estimation; periodic likelihood function; radar baseline; radar heading angle; radar wavelength; rugged terrain; scatterer height; terrain mapping; viewing geometries; geophysical signal processing; maximum likelihood estimation; radar signal processing; radiowave interferometry; remote sensing by radar; synthetic aperture radar; terrain mapping;},
    
    }
    


  6. C. Elachi, S. Wall, M. Allison, Y. Anderson, R. Boehmer, P. Callahan, P. Encrenaz, E. Flamini, G. Franceschetti, Y. Gim, G. Hamilton, S. Hensley, M. Janssen, W. Johnson, K. Kelleher, R. Kirk, R. Lopes, R. Lorenz, J. Lunine, D. Muhleman, S. Ostro, F. Paganelli, G. Picardi, F. Posa, L. Roth, R. Seu, S. Shaffer, L. Soderblom, B. Stiles, E. Stofan, S. Vetrella, R. West, C. Wood, L. Wye, and H. Zebker. Cassini Radar Views the Surface of Titan. Science, 308(5724):970-974, 2005. Keyword(s): SAR Processing, Cassini Radar, Saturn, astronomical instruments, planetary satellites, radar applications, radioastronomy, space vehicles, Cassini Saturn Mission, Cassini Titan Radar Mapper, Titan, antenna configuration, design constraints, multimode radar, radar modes, surface imaging, topographic mapping, Instruments, Laser radar, Moon, Optical design, Payloads, Probes, Radar antennas, Radar imaging, Saturn, Surface topography.
    Abstract: The Cassini Titan Radar Mapper imaged about 1% of Titan's surface at a resolution of ~0.5 kilometer, and larger areas of the globe in lower resolution modes. The images reveal a complex surface, with areas of low relief and a variety of geologic features suggestive of dome-like volcanic constructs, flows, and sinuous channels. The surface appears to be young, with few impact craters. Scattering and dielectric properties are consistent with porous ice or organics. Dark patches in the radar images show high brightness temperatures and high emissivity and are consistent with frozen hydrocarbons.

    @Article{elachiEtAlScience2005CassiniRadarImagesTitan,
    author = {Elachi, C. and Wall, S. and Allison, M. and Anderson, Y. and Boehmer, R. and Callahan, P. and Encrenaz, P. and Flamini, E. and Franceschetti, G. and Gim, Y. and Hamilton, G. and Hensley, S. and Janssen, M. and Johnson, W. and Kelleher, K. and Kirk, R. and Lopes, R. and Lorenz, R. and Lunine, J. and Muhleman, D. and Ostro, S. and Paganelli, F. and Picardi, G. and Posa, F. and Roth, L. and Seu, R. and Shaffer, S. and Soderblom, L. and Stiles, B. and Stofan, E. and Vetrella, S. and West, R. and Wood, C. and Wye, L. and Zebker, H.},
    title = {Cassini Radar Views the Surface of Titan},
    journal = {Science},
    year = {2005},
    volume = {308},
    number = {5724},
    pages = {970-974},
    abstract = {The Cassini Titan Radar Mapper imaged about 1% of Titan's surface at a resolution of ~0.5 kilometer, and larger areas of the globe in lower resolution modes. The images reveal a complex surface, with areas of low relief and a variety of geologic features suggestive of dome-like volcanic constructs, flows, and sinuous channels. The surface appears to be young, with few impact craters. Scattering and dielectric properties are consistent with porous ice or organics. Dark patches in the radar images show high brightness temperatures and high emissivity and are consistent with frozen hydrocarbons.},
    doi = {10.1126/science.1109919},
    eprint = {http://www.sciencemag.org/content/308/5724/970.full.pdf},
    file = {:elachiEtAlScience2005CassiniRadarImagesTitan.pdf:PDF},
    keywords = {SAR Processing, Cassini Radar, Saturn;astronomical instruments;planetary satellites;radar applications;radioastronomy;space vehicles;Cassini Saturn Mission;Cassini Titan Radar Mapper;Titan;antenna configuration;design constraints;multimode radar;radar modes;surface imaging;topographic mapping;Instruments;Laser radar;Moon;Optical design;Payloads;Probes;Radar antennas;Radar imaging;Saturn;Surface topography},
    owner = {ofrey},
    pdf = {../../../docs/elachiEtAlScience2005CassiniRadarImagesTitan.pdf},
    url = {http://www.sciencemag.org/content/308/5724/970.abstract},
    
    }
    


  7. Alessandro Ferretti, Marco Bianchi, Claudio Prati, and Fabio Rocca. Higher-Order Permanent Scatterers Analysis. EURASIP Journal on Advances in Signal Processing, 2005(20):609604, 2005. Keyword(s): SAR Processing, PSI, Persistent Scatterer Interferometry, Differential SAR Interferometry, SAR Tomography, Permanent scatterers, geodesy, geophysical techniques, remote sensing by radar, synthetic aperture radar, terrain mapping, topography (Earth)InSAR, SAR interferometry, atmospheric disturbance, atmospheric phase screen, differential interferometry, geodesy, geometrical decorrelation, geophysical measurement technique, land surface topography, permanent scatterer, radar remote sensing, stable natural reflector, surface deformation monitoring, synthetic aperture radar, terrain mapping, topographic profile reconstruction.
    Abstract: The permanent scatterers (PS) technique is a multi-interferogram algorithm for DInSAR analyses developed in the late nineties to overcome the difficulties related to the conventional approach, namely, phase decorrelation and atmospheric effects. The successful application of this technology to many geophysical studies is now pushing toward further improvements and optimizations. A possible strategy to increase the number of radar targets that can be exploited for surface deformation monitoring is the adoption of parametric super-resolution algorithms that can cope with multiple scattering centres within the same resolution cell. In fact, since a PS is usually modelled as a single pointwise scatterer dominating the background clutter, radar targets having cross-range dimension exceeding a few meters can be lost (at least in C-band datasets), due to geometrical decorrelation phenomena induced in the high normal baseline interferograms of the dataset. In this paper, the mathematical framework related to higher-order SAR interferometry is presented as well as preliminary results obtained on simulated and real data. It is shown how the PS density can be increased at the price of a higher computational load.

    @Article{ferrettiBianchiPratiRoccaEURASIP2005HigherOrderPSI,
    author = {Ferretti, Alessandro and Bianchi, Marco and Prati, Claudio and Rocca, Fabio},
    title = {Higher-Order Permanent Scatterers Analysis},
    journal = {EURASIP Journal on Advances in Signal Processing},
    year = {2005},
    volume = {2005},
    number = {20},
    pages = {609604},
    issn = {1687-6180},
    abstract = {The permanent scatterers (PS) technique is a multi-interferogram algorithm for DInSAR analyses developed in the late nineties to overcome the difficulties related to the conventional approach, namely, phase decorrelation and atmospheric effects. The successful application of this technology to many geophysical studies is now pushing toward further improvements and optimizations. A possible strategy to increase the number of radar targets that can be exploited for surface deformation monitoring is the adoption of parametric super-resolution algorithms that can cope with multiple scattering centres within the same resolution cell. In fact, since a PS is usually modelled as a single pointwise scatterer dominating the background clutter, radar targets having cross-range dimension exceeding a few meters can be lost (at least in C-band datasets), due to geometrical decorrelation phenomena induced in the high normal baseline interferograms of the dataset. In this paper, the mathematical framework related to higher-order SAR interferometry is presented as well as preliminary results obtained on simulated and real data. It is shown how the PS density can be increased at the price of a higher computational load.},
    doi = {10.1155/ASP.2005.3231},
    file = {:ferrettiBianchiPratiRoccaEURASIP2005HigherOrderPSI.pdf:PDF},
    keywords = {SAR Processing, PSI, Persistent Scatterer Interferometry, Differential SAR Interferometry, SAR Tomography, Permanent scatterers, geodesy, geophysical techniques, remote sensing by radar, synthetic aperture radar, terrain mapping, topography (Earth)InSAR, SAR interferometry, atmospheric disturbance, atmospheric phase screen, differential interferometry, geodesy, geometrical decorrelation, geophysical measurement technique, land surface topography, permanent scatterer, radar remote sensing, stable natural reflector, surface deformation monitoring, synthetic aperture radar, terrain mapping, topographic profile reconstruction},
    pdf = {../../../docs/ferrettiBianchiPratiRoccaEURASIP2005HigherOrderPSI.pdf},
    url = {http://asp.eurasipjournals.com/content/2005/20/609604},
    
    }
    


  8. Gianfranco Fornaro, Giorgio Franceschetti, and Stefano Perna. Motion compensation errors: effects on the accuracy of airborne SAR images. IEEE Transactions on Aerospace and Electronic Systems, 41(4):1338-1352, October 2005. Keyword(s): SAR Processing, Motion Compensation, Residual Motion Errors, Autofocus, Airborne SAR, airborne radar, interferometry, motion compensation, radar imaging, synthetic aperture radar airborne SAR images, digital elevation model inaccuracies, motion compensation errors, phase errors, positioning measurement instrument, repeat pass airborne interferometry, residual uncompensated motion errors, synthetic aperture radar.
    Abstract: This work addresses the study of the effect of residual uncompensated motion errors due to positioning measurement instrument and digital elevation model inaccuracies on the accuracy of airborne synthetic aperture radar (SAR) images. It is shown that these not only introduce phase errors following pure geometric considerations, but they also cause additional aberrations related to their interaction with the SAR processing procedure. Extension to the repeat pass airborne interferometry is also included to show their impact on the resulting interferograms.

    @Article{fornaroFranceschettiPernaTGRS2005MoCompErrorsOnInSAR,
    author = {Fornaro, Gianfranco and Franceschetti, Giorgio and Perna, Stefano},
    title = {Motion compensation errors: effects on the accuracy of airborne {SAR} images},
    journal = {IEEE Transactions on Aerospace and Electronic Systems},
    year = {2005},
    volume = {41},
    number = {4},
    pages = {1338-1352},
    month = oct,
    abstract = {This work addresses the study of the effect of residual uncompensated motion errors due to positioning measurement instrument and digital elevation model inaccuracies on the accuracy of airborne synthetic aperture radar (SAR) images. It is shown that these not only introduce phase errors following pure geometric considerations, but they also cause additional aberrations related to their interaction with the SAR processing procedure. Extension to the repeat pass airborne interferometry is also included to show their impact on the resulting interferograms.},
    doi = {10.1109/TAES.2005.1561879},
    file = {:fornaroFranceschettiPernaTGRS2005MoCompErrorsOnInSAR.pdf:PDF},
    keywords = {SAR Processing, Motion Compensation, Residual Motion Errors, Autofocus,Airborne SAR, airborne radar, interferometry, motion compensation, radar imaging, synthetic aperture radar airborne SAR images, digital elevation model inaccuracies, motion compensation errors, phase errors, positioning measurement instrument, repeat pass airborne interferometry, residual uncompensated motion errors, synthetic aperture radar},
    pdf = {../../../docs/FornaroFranceschettiPerna05.pdf},
    url = {http://ieeexplore.ieee.org/iel5/7/33161/01561879.pdf},
    
    }
    


  9. Gianfranco Fornaro, Fabrizio Lombardini, and Francesco Serafino. Three-dimensional multipass SAR focusing: experiments with long-term spaceborne data. IEEE Trans. Geosci. Remote Sens., 43(4):702-714, 2005. Keyword(s): SAR Processing, SAR Tomography, Tomography, Interferometry, airborne SAR, Spaceborne SAR, stereo image processing, three-dimensional multipass SAR focusing, ERS data, ERS multipass tomography, European Remote Sensing satellite, SAR interferometry, atmospheric variations, azimuth-range resolution cell, critical nonlinear inversion steps, ground pixel, height profile reconstruction, limited spatial-coverage, limited time-span, multibaseline 3D SAR focusing, multiple targets, radiation penetration, scattering mechanisms, scene deformations, side-looking geometry, space-varying phase calibration, tomographic processing, Multibaseline, multipass, three-dimensional focusing.
    Abstract: Synthetic aperture radar (SAR) interferometry is a modern efficient technique that allows reconstructing the height profile of the observed scene. However, apart for the presence of critical nonlinear inversion steps, particularly crucial in abrupt topography scenarios, it does not allow one to separate different scattering mechanisms in the elevation (height) direction within the ground pixel. Overlay of scattering at different elevations in the same azimuth-range resolution cell can be due either to the penetration of the radiation below the surface or to perspective ambiguities caused by the side-looking geometry. Multibaseline three-dimensional (3-D) SAR focusing allows overcoming such a limitation and has thus raised great interest in the recent research. First results with real data have been only obtained in the laboratory and with airborne systems, or with limited time-span and spatial-coverage spaceborne data. This work presents a novel approach for the tomographic processing of European Remote Sensing satellite (ERS) real data for extended scenes and long time span. Besides facing problems common to the airborne case, such as the nonuniformly spaced passes, this processing requires tackling additional difficulties specific to the spaceborne case, in particular a space-varying phase calibration of the data due to atmospheric variations and possible scene deformations occurring for years-long temporal spans. First results are presented that confirm the capability of ERS multipass tomography to resolve multiple targets within the same azimuth-range cell and to map the 3-D scattering properties of the illuminated scene.

    @Article{fornaroLombardiniSerafino05:MultipassTomo3D,
    Title = {Three-dimensional multipass {SAR} focusing: experiments with long-term spaceborne data},
    Author = {Gianfranco Fornaro and Fabrizio Lombardini and Francesco Serafino},
    Number = {4},
    Pages = {702--714},
    Url = {http://ieeexplore.ieee.org/iel5/36/30591/01411976.pdf},
    Volume = {43},
    Year = {2005},
    Abstract = {Synthetic aperture radar (SAR) interferometry is a modern efficient technique that allows reconstructing the height profile of the observed scene. However, apart for the presence of critical nonlinear inversion steps, particularly crucial in abrupt topography scenarios, it does not allow one to separate different scattering mechanisms in the elevation (height) direction within the ground pixel. Overlay of scattering at different elevations in the same azimuth-range resolution cell can be due either to the penetration of the radiation below the surface or to perspective ambiguities caused by the side-looking geometry. Multibaseline three-dimensional (3-D) SAR focusing allows overcoming such a limitation and has thus raised great interest in the recent research. First results with real data have been only obtained in the laboratory and with airborne systems, or with limited time-span and spatial-coverage spaceborne data. This work presents a novel approach for the tomographic processing of European Remote Sensing satellite (ERS) real data for extended scenes and long time span. Besides facing problems common to the airborne case, such as the nonuniformly spaced passes, this processing requires tackling additional difficulties specific to the spaceborne case, in particular a space-varying phase calibration of the data due to atmospheric variations and possible scene deformations occurring for years-long temporal spans. First results are presented that confirm the capability of ERS multipass tomography to resolve multiple targets within the same azimuth-range cell and to map the 3-D scattering properties of the illuminated scene.},
    Journal = {IEEE Trans. Geosci. Remote Sens.},
    Keywords = {SAR Processing, SAR Tomography, Tomography, Interferometry, airborne SAR, Spaceborne SAR, stereo image processing, three-dimensional multipass SAR focusing, ERS data, ERS multipass tomography, European Remote Sensing satellite, SAR interferometry, atmospheric variations, azimuth-range resolution cell, critical nonlinear inversion steps, ground pixel, height profile reconstruction, limited spatial-coverage, limited time-span, multibaseline 3D SAR focusing, multiple targets, radiation penetration, scattering mechanisms, scene deformations, side-looking geometry, space-varying phase calibration, tomographic processing, Multibaseline, multipass, three-dimensional focusing},
    Owner = {ofrey},
    Pdf = {../../../docs/fornaroLombardiniSerafino05.pdf} 
    }
    


  10. G. Fornaro, A. Pauciullo, and E. Sansosti. Phase difference-based multichannel phase unwrapping. IEEE Transactions on Image Processing, 14(7):960-972, July 2005. Keyword(s): image processing, maximum likelihood phase unwrapping algorithm, phase difference-based multichannel phase unwrapping algorithm, image processing, maximum likelihood estimation, Algorithms, Artificial Intelligence, Image Enhancement, Image Interpretation, Computer-Assisted, Imaging, Three-Dimensional, Information Storage and Retrieval, Pattern Recognition, Automated, Radar, Subtraction Technique.
    Abstract: This work addresses the derivation of the phase difference-based maximum likelihood (ML) phase unwrapping algorithm. To this end, we derive the joint statistics of the phase differences on a two-dimensional grid for the multichannel case, where several scaled wrapped phase values are available. Subsequently, we determine and study the structure of the phase difference-based ML estimator and compare it to known phase unwrapping techniques. This work allows us to frame single and multichannel algorithms in a common formulation. Moreover, among the known single-channel phase difference-based procedures, we identify those attaining an ML solution. We also show that multichannel phase difference-based and, recently proposed, phase-based ML algorithms achieve equivalent solutions.

    @Article{fornaroPauciulloSansostiTIP2005PhaseUnwrapping,
    Title = {Phase difference-based multichannel phase unwrapping},
    Author = {Fornaro, G. and Pauciullo, A. and Sansosti, E.},
    Doi = {10.1109/TIP.2005.849302},
    ISSN = {1057-7149},
    Month = jul,
    Number = {7},
    Pages = {960-972},
    Volume = {14},
    Year = {2005},
    Abstract = {This work addresses the derivation of the phase difference-based maximum likelihood (ML) phase unwrapping algorithm. To this end, we derive the joint statistics of the phase differences on a two-dimensional grid for the multichannel case, where several scaled wrapped phase values are available. Subsequently, we determine and study the structure of the phase difference-based ML estimator and compare it to known phase unwrapping techniques. This work allows us to frame single and multichannel algorithms in a common formulation. Moreover, among the known single-channel phase difference-based procedures, we identify those attaining an ML solution. We also show that multichannel phase difference-based and, recently proposed, phase-based ML algorithms achieve equivalent solutions.},
    Journal = {IEEE Transactions on Image Processing},
    Keywords = {image processing;maximum likelihood phase unwrapping algorithm;phase difference-based multichannel phase unwrapping algorithm;image processing;maximum likelihood estimation;Algorithms;Artificial Intelligence;Image Enhancement;Image Interpretation, Computer-Assisted;Imaging, Three-Dimensional;Information Storage and Retrieval;Pattern Recognition, Automated;Radar;Subtraction Technique} 
    }
    


  11. F. Gini and F. Lombardini. Multibaseline Cross-Track SAR Interferometry: A Signal Processing Perspective. IEEE Aerospace and Electronic Systems Magazine, 20(8):71-93, 2005. Keyword(s): SAR Processing, SAR Tomography, Tomography, AWGN, array signal processing, radar signal processing, speckle, surface topography measurement, synthetic aperture radar, InSAR, MB SAR tomography, SAR signal processing, ULA, XTI-SAR, additive white Gaussian noise, multibaseline cross-track SAR interferometry, multicomponent signal detection, multiplicative noise, natural layover area reflectivity, nonparametric spectral estimation, nonperfectly calibrated arrays, parametric spectral estimation, radar imaging speckle, semitransparent volume scattering layers, surface topography measurement, synthetic aperture radar interferometry, uniform linear array.
    Abstract: Synthetic aperture radar interferometry (InSAR) is a powerful and increasingly expanding technique for measuring the topography of a surface, its changes over both short- and long-time scale, and other changes in the detailed characteristics of the surface. We provide a tutorial description of recent results on multibaseline (MB) InSAR processing. The main focus is on the problem of retrieving both heights and radar reflectivities of natural layover areas by means of a cross-track InSAR (XTI-SAR) system with a uniform linear array (ULA). It is formulated as the problem of detecting and estimating a multicomponent signal corrupted by multiplicative noise - the speckle in the radar imaging jargon - and by additive white Gaussian noise. Application to the InSAR problem of both nonparametric and parametric modern spectral estimation techniques is described. The problem of estimating the number of signal components in the presence of speckle is also addressed. Finally, a brief mention is given to recent research trends on robust methods for nonperfectly calibrated arrays, on processing for non-ULA configurations, and on MB SAR tomography, which is an extension of MB SAR interferometry for the full 3D mapping of semitransparent volume scattering layers. The state of the art of other advanced multichannel interferometric techniques is also briefly recalled.

    @Article{giniLombardini05:Tomo,
    Title = {{Multibaseline Cross-Track {SAR} Interferometry: A Signal Processing Perspective}},
    Author = {Gini, F. and Lombardini, F.},
    ISSN = {0885-8985},
    Number = {8},
    Pages = {71--93},
    Url = {http://ieeexplore.ieee.org/iel5/62/32201/01499278.pdf},
    Volume = {20},
    Year = {2005},
    Abstract = {Synthetic aperture radar interferometry (InSAR) is a powerful and increasingly expanding technique for measuring the topography of a surface, its changes over both short- and long-time scale, and other changes in the detailed characteristics of the surface. We provide a tutorial description of recent results on multibaseline (MB) InSAR processing. The main focus is on the problem of retrieving both heights and radar reflectivities of natural layover areas by means of a cross-track InSAR (XTI-SAR) system with a uniform linear array (ULA). It is formulated as the problem of detecting and estimating a multicomponent signal corrupted by multiplicative noise - the speckle in the radar imaging jargon - and by additive white Gaussian noise. Application to the InSAR problem of both nonparametric and parametric modern spectral estimation techniques is described. The problem of estimating the number of signal components in the presence of speckle is also addressed. Finally, a brief mention is given to recent research trends on robust methods for nonperfectly calibrated arrays, on processing for non-ULA configurations, and on MB SAR tomography, which is an extension of MB SAR interferometry for the full 3D mapping of semitransparent volume scattering layers. The state of the art of other advanced multichannel interferometric techniques is also briefly recalled.},
    Journal = {IEEE Aerospace and Electronic Systems Magazine},
    Keywords = {SAR Processing, SAR Tomography, Tomography, AWGN, array signal processing, radar signal processing, speckle, surface topography measurement, synthetic aperture radar, InSAR, MB SAR tomography, SAR signal processing, ULA, XTI-SAR, additive white Gaussian noise, multibaseline cross-track SAR interferometry, multicomponent signal detection, multiplicative noise, natural layover area reflectivity, nonparametric spectral estimation, nonperfectly calibrated arrays, parametric spectral estimation, radar imaging speckle, semitransparent volume scattering layers, surface topography measurement, synthetic aperture radar interferometry, uniform linear array},
    Owner = {ofrey},
    Pdf = {../../../docs/giniLombardiniTomo05.pdf} 
    }
    


  12. J.A. Given and W.R. Schmidt. Generalized ISAR - part I: an optimal method for imaging large naval vessels. Image Processing, IEEE Transactions on, 14(11):1783 -1791, November 2005. Keyword(s): Doppler rate, fixed linear combination, generalized ISAR, high-accuracy three-dimensional location, inverse synthetic aperture radar, large naval vessel imaging, localized scatterer, moderate intensity ship roll, optimal method, radar cross section, radar signal processing, electromagnetic wave scattering, military radar, radar cross-sections, radar imaging, ships, synthetic aperture radar, Algorithms, Artificial Intelligence, Image Enhancement, Image Interpretation, Computer-Assisted, Imaging, Three-Dimensional, Information Storage and Retrieval, Pattern Recognition, Automated, Radar, Ships;.
    Abstract: We describe a generalized inverse synthetic aperture radar (ISAR) process that performs well under a wide variety of conditions common to the naval ISAR tests of large vessels. In particular, the generalized ISAR process performs well in the presence of moderate intensity ship roll. The process maps localized scatterers onto peaks on the ISAR plot. However, in a generalized ISAR plot, each of the two coordinates of a peak is a fixed linear combination of the three ship coordinates of the scatterer causing the peak. Combining this process with interferometry will then provide high-accuracy three-dimensional location of the important scatterers on a ship. We show that ISAR can be performed in the presence of simultaneous roll and aspect change, provided the two Doppler rates are not too close in magnitude. We derive the equations needed for generalized ISAR, both roll driven and aspect driven, and test them against simulations performed in a variety of conditions, including large roll amplitudes.

    @Article{givenSchmidt2005partI,
    Title = {Generalized ISAR - part I: an optimal method for imaging large naval vessels},
    Author = {Given, J.A. and Schmidt, W.R.},
    Doi = {10.1109/TIP.2005.857283},
    ISSN = {1057-7149},
    Month = nov,
    Number = {11},
    Pages = {1783 -1791},
    Volume = {14},
    Year = {2005},
    Abstract = {We describe a generalized inverse synthetic aperture radar (ISAR) process that performs well under a wide variety of conditions common to the naval ISAR tests of large vessels. In particular, the generalized ISAR process performs well in the presence of moderate intensity ship roll. The process maps localized scatterers onto peaks on the ISAR plot. However, in a generalized ISAR plot, each of the two coordinates of a peak is a fixed linear combination of the three ship coordinates of the scatterer causing the peak. Combining this process with interferometry will then provide high-accuracy three-dimensional location of the important scatterers on a ship. We show that ISAR can be performed in the presence of simultaneous roll and aspect change, provided the two Doppler rates are not too close in magnitude. We derive the equations needed for generalized ISAR, both roll driven and aspect driven, and test them against simulations performed in a variety of conditions, including large roll amplitudes.},
    Journal = {Image Processing, IEEE Transactions on},
    Keywords = {Doppler rate;fixed linear combination;generalized ISAR;high-accuracy three-dimensional location;inverse synthetic aperture radar;large naval vessel imaging;localized scatterer;moderate intensity ship roll;optimal method;radar cross section;radar signal processing;electromagnetic wave scattering;military radar;radar cross-sections;radar imaging;ships;synthetic aperture radar;Algorithms;Artificial Intelligence;Image Enhancement;Image Interpretation, Computer-Assisted;Imaging, Three-Dimensional;Information Storage and Retrieval;Pattern Recognition, Automated;Radar;Ships;} 
    }
    


  13. J.A. Given and W.R. Schmidt. Generalized ISAR-part II: interferometric techniques for three-dimensional location of scatterers. Image Processing, IEEE Transactions on, 14(11):1792 -1797, nov. 2005. Keyword(s): aspect angle, diagnostic inverse synthetic aperture radar, interferometric ISAR optimization, naval vessel, radio-frequency scatterer, roll angle, ship orientation, ship position, specialized signal processing, substantial Doppler return, three-dimensional location, Doppler radar, electromagnetic wave scattering, military radar, radar resolution, radiowave interferometry, ships, synthetic aperture radar, Algorithms, Artificial Intelligence, Image Enhancement, Image Interpretation, Computer-Assisted, Imaging, Three-Dimensional, Information Storage and Retrieval, Interferometry, Pattern Recognition, Automated, Radar, Ships;.
    Abstract: This paper is the second part of a study dedicated to optimizing diagnostic inverse synthetic aperture radar (ISAR) studies of large naval vessels. The method developed here provides accurate determination of the position of important radio-frequency scatterers by combining accurate knowledge of ship position and orientation with specialized signal processing. The method allows for the simultaneous presence of substantial Doppler returns from both change of roll angle and change of aspect angle by introducing generalized ISAR ates. The first paper provides two modes of interpreting ISAR plots, one valid when roll Doppler is dominant, the other valid when the aspect angle Doppler is dominant. Here, we provide, for each type of ISAR plot technique, a corresponding interferometric ISAR (InSAR) technique. The former, aspect-angle dominated InSAR, is a generalization of standard InSAR; the latter, roll-angle dominated InSAR, seems to be new to this work. Both methods are shown to be efficient at identifying localized scatterers under simulation conditions.

    @Article{givenSchmidt2005partII,
    author = {Given, J.A. and Schmidt, W.R.},
    journal = {Image Processing, IEEE Transactions on},
    title = {Generalized ISAR-part II: interferometric techniques for three-dimensional location of scatterers},
    year = {2005},
    issn = {1057-7149},
    month = {nov.},
    number = {11},
    pages = {1792 -1797},
    volume = {14},
    abstract = {This paper is the second part of a study dedicated to optimizing diagnostic inverse synthetic aperture radar (ISAR) studies of large naval vessels. The method developed here provides accurate determination of the position of important radio-frequency scatterers by combining accurate knowledge of ship position and orientation with specialized signal processing. The method allows for the simultaneous presence of substantial Doppler returns from both change of roll angle and change of aspect angle by introducing generalized ISAR ates. The first paper provides two modes of interpreting ISAR plots, one valid when roll Doppler is dominant, the other valid when the aspect angle Doppler is dominant. Here, we provide, for each type of ISAR plot technique, a corresponding interferometric ISAR (InSAR) technique. The former, aspect-angle dominated InSAR, is a generalization of standard InSAR; the latter, roll-angle dominated InSAR, seems to be new to this work. Both methods are shown to be efficient at identifying localized scatterers under simulation conditions.},
    doi = {10.1109/TIP.2005.857285},
    keywords = {aspect angle;diagnostic inverse synthetic aperture radar;interferometric ISAR optimization;naval vessel;radio-frequency scatterer;roll angle;ship orientation;ship position;specialized signal processing;substantial Doppler return;three-dimensional location;Doppler radar;electromagnetic wave scattering;military radar;radar resolution;radiowave interferometry;ships;synthetic aperture radar;Algorithms;Artificial Intelligence;Image Enhancement;Image Interpretation, Computer-Assisted;Imaging, Three-Dimensional;Information Storage and Retrieval;Interferometry;Pattern Recognition, Automated;Radar;Ships;},
    
    }
    


  14. Young-Kyun Kong, Byung-Lae Cho, and Young-Soo Kim. Ambiguity-free Doppler centroid estimation technique for airborne SAR using the Radon transform. IEEE Trans. Geosci. Remote Sens., 43(4):715-721, 2005. Keyword(s): SAR Processing, Doppler Centroid Estimation, Doppler effect, Radon transforms, airborne radar, geophysical signal processing, geophysical techniques, radar clutter, synthetic aperture radar, Doppler Ambiguity Resolver, DAR, Radon transform, SAR image, SAR signal processing, airborne SAR, ambiguity-free Doppler centroid estimation technique, clutter-lock, geometric distortion, geometry-based Doppler estimator, radiometric error, signal-to-noise ratio, squint angle, synthetic aperture radar, Clutter-lock.
    Abstract: In synthetic aperture radar (SAR) signal processing, the Doppler centroid estimation technique, called the ``clutter-lock'', is important because it is related to the signal-to-noise ratio, geometric distortion, and radiometric error of the final SAR image. Conventional algorithms have either ambiguity problems or somewhat high computational load. Using the fact that the Doppler centroid and the squint angle are directly related, we propose an ambiguity-free Doppler centroid estimation technique using Radon transform, named geometry-based Doppler estimator. The proposed algorithm is computationally efficient and shows good performance of estimating the absolute Doppler centroid.

    @Article{kongChoKim2005:DopCenEstimRadon,
    Title = {Ambiguity-free Doppler centroid estimation technique for airborne SAR using the Radon transform},
    Author = {Kong, Young-Kyun and Cho, Byung-Lae and Kim, Young-Soo},
    ISSN = {0196-2892},
    Number = {4},
    Pages = {715--721},
    Url = {http://ieeexplore.ieee.org/iel5/36/30591/01411977.pdf},
    Volume = {43},
    Year = {2005},
    Abstract = {In synthetic aperture radar (SAR) signal processing, the Doppler centroid estimation technique, called the ``clutter-lock'', is important because it is related to the signal-to-noise ratio, geometric distortion, and radiometric error of the final SAR image. Conventional algorithms have either ambiguity problems or somewhat high computational load. Using the fact that the Doppler centroid and the squint angle are directly related, we propose an ambiguity-free Doppler centroid estimation technique using Radon transform, named geometry-based Doppler estimator. The proposed algorithm is computationally efficient and shows good performance of estimating the absolute Doppler centroid.},
    Journal = {IEEE Trans. Geosci. Remote Sens.},
    Keywords = {SAR Processing, Doppler Centroid Estimation, Doppler effect, Radon transforms, airborne radar, geophysical signal processing, geophysical techniques, radar clutter, synthetic aperture radar, Doppler Ambiguity Resolver, DAR, Radon transform, SAR image, SAR signal processing, airborne SAR, ambiguity-free Doppler centroid estimation technique, clutter-lock, geometric distortion, geometry-based Doppler estimator, radiometric error, signal-to-noise ratio, squint angle, synthetic aperture radar, Clutter-lock},
    Owner = {ofrey},
    Pdf = {../../../docs/kongChoKim2005.pdf},
    Timestamp = {2006.04.28} 
    }
    


  15. Fabrizio Lombardini. Differential tomography: a new framework for SAR interferometry. IEEE Trans. Geosci. Remote Sens., 43(1):37-44, 2005. Keyword(s): SAR Processing, backscatter, data acquisition, geophysical signal processing, geophysical techniques, multidimensional signal processing, radiowave interferometry, remote sensing by radar, spectral analysis, synthetic aperture radar, Tomography, SAR interferometry, baseline-time acquisition patterns, bidimensional baseline-time spectral analysis, data-dependent bidimensional spectral estimation, SAR Tomography, differential SAR tomography, differential tomography, electromagnetic tomography, elevation-velocity resolution, interferometric technique, joint baseline-time processing, layover scatterers, motion conditions, multibaseline SAR tomography, multidimensional signal processing, multiple scatterers, sparse sampling, synthetic aperture radar.
    Abstract: A new interferometric mode crossing the differential synthetic aperture radar (SAR) interferometry and multibaseline SAR tomography concepts, that can be termed differential SAR tomography, is proposed. Its potentials, coming from the joint elevation-velocity resolution capability of multiple scatterers, are discussed. Processing is cast in a bidimensional baseline-time spectral analysis framework, with sparse sampling. The use of a modern data-dependent bidimensional spectral estimator is proposed for joint baseline-time processing. Simulated results are reported for different baseline-time acquisition patterns and two motion conditions of layover scatterers, showing that this new challenging interferometric technique is promising.

    @Article{lombadini05:DiffTomo,
    Title = {Differential tomography: a new framework for {SAR} interferometry},
    Author = {Lombardini, Fabrizio},
    Number = {1},
    Pages = {37-44},
    Url = {http://ieeexplore.ieee.org/iel5/36/30123/01381617.pdf},
    Volume = {43},
    Year = {2005},
    Abstract = {A new interferometric mode crossing the differential synthetic aperture radar (SAR) interferometry and multibaseline SAR tomography concepts, that can be termed differential SAR tomography, is proposed. Its potentials, coming from the joint elevation-velocity resolution capability of multiple scatterers, are discussed. Processing is cast in a bidimensional baseline-time spectral analysis framework, with sparse sampling. The use of a modern data-dependent bidimensional spectral estimator is proposed for joint baseline-time processing. Simulated results are reported for different baseline-time acquisition patterns and two motion conditions of layover scatterers, showing that this new challenging interferometric technique is promising.},
    Journal = {IEEE Trans. Geosci. Remote Sens.},
    Keywords = {SAR Processing, backscatter, data acquisition, geophysical signal processing, geophysical techniques, multidimensional signal processing, radiowave interferometry, remote sensing by radar, spectral analysis, synthetic aperture radar, Tomography, SAR interferometry, baseline-time acquisition patterns, bidimensional baseline-time spectral analysis, data-dependent bidimensional spectral estimation, SAR Tomography, differential SAR tomography, differential tomography, electromagnetic tomography, elevation-velocity resolution, interferometric technique, joint baseline-time processing, layover scatterers, motion conditions, multibaseline SAR tomography, multidimensional signal processing, multiple scatterers, sparse sampling, synthetic aperture radar},
    Owner = {ofrey},
    Pdf = {../../../docs/lombardini05.pdf} 
    }
    


  16. Fabrizio Lombardini and Fulvio Gini. Model order selection in multi-baseline interferometric radar systems. EURASIP Journal on Advances in Signal Processing, 2005(20):1-14, 2005.
    @Article{LombardiniGiniEURASIPSignal2005ModelOrderSelection,
    author = {Lombardini, Fabrizio and Gini, Fulvio},
    title = {Model order selection in multi-baseline interferometric radar systems},
    year = {2005},
    volume = {2005},
    number = {20},
    pages = {1--14},
    journal = {EURASIP Journal on Advances in Signal Processing},
    owner = {ofrey},
    publisher = {Springer},
    
    }
    


  17. L. Noferini, M. Pieraccini, D. Mecatti, G. Luzi, C. Atzeni, A. Tamburini, and M. Broccolato. Permanent scatterers analysis for atmospheric correction in ground-based SAR interferometry. IEEE Trans. Geosci. Remote Sens., 43(7):1459-1471, July 2005. Keyword(s): SAR Processing, Persistent Scatterer Interferometry, PSI, Ground-based SAR, Citrin Valley, Italy, atmospheric correction, atmospheric disturbance, atmospheric effects, building structural change detection, ground-based SAR interferometry, landslide monitoring, permanent scatterers analysis, spaceborne SAR interferometry, synthetic aperture radar, terrain monitoring, remote sensing by radar, synthetic aperture radar, terrain mapping, topography (Earth);.
    Abstract: Ground-based synthetic aperture radar (GB-SAR) interferometry has already been recognized as a powerful tool, complementary or alternative to spaceborne SAR interferometry, for terrain monitoring, and for detecting structural changes in buildings. It has been noted that, in spite of the very short range, compared with the satellite configuration, in GB-SAR measurement the disturbances due to atmospheric effects cannot be neglected either. The analysis of the interferometric phases of very coherent points, called permanent scatterers (PSs), allows the evaluation of the atmospheric disturbance and the possibility of removing it. In this paper, the PS analysis is carried out both on a test site facility and on a real campaign (Citrin Valley, Italy) that provided data with a temporal baseline of about ten months.

    @Article{noferiniPieracciniMecattiLuziAtzeniTamburiniBroccolato2005PSIAtmoGroundbased,
    Title = {Permanent scatterers analysis for atmospheric correction in ground-based {SAR} interferometry},
    Author = {Noferini, L. and Pieraccini, M. and Mecatti, D. and Luzi, G. and Atzeni, C. and Tamburini, A. and Broccolato, M.},
    Doi = {10.1109/TGRS.2005.848707},
    ISSN = {0196-2892},
    Month = jul,
    Number = {7},
    Pages = {1459-1471},
    Volume = {43},
    Year = {2005},
    Abstract = {Ground-based synthetic aperture radar (GB-SAR) interferometry has already been recognized as a powerful tool, complementary or alternative to spaceborne SAR interferometry, for terrain monitoring, and for detecting structural changes in buildings. It has been noted that, in spite of the very short range, compared with the satellite configuration, in GB-SAR measurement the disturbances due to atmospheric effects cannot be neglected either. The analysis of the interferometric phases of very coherent points, called permanent scatterers (PSs), allows the evaluation of the atmospheric disturbance and the possibility of removing it. In this paper, the PS analysis is carried out both on a test site facility and on a real campaign (Citrin Valley, Italy) that provided data with a temporal baseline of about ten months.},
    Journal = {IEEE Trans. Geosci. Remote Sens.},
    Keywords = {SAR Processing, Persistent Scatterer Interferometry, PSI, Ground-based SAR, Citrin Valley; Italy; atmospheric correction; atmospheric disturbance; atmospheric effects; building structural change detection; ground-based SAR interferometry; landslide monitoring; permanent scatterers analysis; spaceborne SAR interferometry; synthetic aperture radar; terrain monitoring; remote sensing by radar; synthetic aperture radar; terrain mapping; topography (Earth);} 
    }
    


  18. Pau Prats, Andreas Reigber, and Jordi J. Mallorqui. Topography-dependent motion compensation for repeat-pass interferometric SAR systems. IEEE Geosci. Remote Sens. Lett., 2(2):206-210, 2005. Keyword(s): SAR Processing, Motion Compensation, Topography-Based Motion Compensation, ESAR, L-Band, Airborne SAR, radar imaging, remote sensing by radar, synthetic aperture radar, Topography, German Aerospace Center E-SAR, DLR, SAR data processing, airborne L-band repeat-pass interferometric data, Interferometry, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm, azimuth compression, azimuth coregistration errors, external digital elevation model, DEM, image enhancement, image registration, impulse response degradation, phase artifacts, repeat-pass interferometric SAR systems, Calibration, image registration, repeat-pass interferometry.
    Abstract: This letter presents a new motion compensation algorithm to process airborne interferometric repeat-pass synthetic aperture radar (SAR) data. It accommodates topography variations during SAR data processing, using an external digital elevation model. The proposed approach avoids phase artifacts, azimuth coregistration errors, and impulse response degradation, which usually appear due to the assumption of a constant reference height during motion compensation. It accurately modifies phase history of all targets before azimuth compression, resulting in an enhanced image quality. Airborne L-band repeat-pass interferometric data of the German Aerospace Center experimental airborne SAR (E-SAR) is used to validate the algorithm.

    @Article{pratsReigberMallorqui05TopographyDepMoCo,
    author = {Prats, Pau and Reigber, Andreas and Mallorqui, Jordi J.},
    journal = {IEEE Geosci. Remote Sens. Lett.},
    title = {{Topography-dependent motion compensation for repeat-pass interferometric SAR systems}},
    year = {2005},
    number = {2},
    pages = {206--210},
    volume = {2},
    abstract = {This letter presents a new motion compensation algorithm to process airborne interferometric repeat-pass synthetic aperture radar (SAR) data. It accommodates topography variations during SAR data processing, using an external digital elevation model. The proposed approach avoids phase artifacts, azimuth coregistration errors, and impulse response degradation, which usually appear due to the assumption of a constant reference height during motion compensation. It accurately modifies phase history of all targets before azimuth compression, resulting in an enhanced image quality. Airborne L-band repeat-pass interferometric data of the German Aerospace Center experimental airborne SAR (E-SAR) is used to validate the algorithm.},
    file = {:pratsReigberMallorqui05TopographyDepMoCo.pdf:PDF},
    keywords = {SAR Processing, Motion Compensation,Topography-Based Motion Compensation, ESAR, L-Band, Airborne SAR, radar imaging, remote sensing by radar, synthetic aperture radar, Topography, German Aerospace Center E-SAR, DLR, SAR data processing, airborne L-band repeat-pass interferometric data, Interferometry, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm, azimuth compression, azimuth coregistration errors, external digital elevation model, DEM, image enhancement, image registration, impulse response degradation, phase artifacts, repeat-pass interferometric SAR systems, Calibration, image registration, repeat-pass interferometry},
    owner = {ofrey},
    pdf = {../../../docs/pratsReigberMallorqui05.pdf},
    url = {http://ieeexplore.ieee.org/iel5/8859/30687/01420306.pdf},
    
    }
    


  19. A. Reigber and L. Ferro-Famil. Interference suppression in synthesized SAR images. IEEE Geosci. Remote Sens. Lett., 2(1):45-49, 2005. Keyword(s): SAR Processsing, filtering theory, interference suppression, radar imaging, radar interference, synthetic aperture radar, German Aerospace Agency, L-Band, ESAR, SAR imaging, data processing, experimental SAR system, filtering theory, focused SAR images, SLC, image degradation, interferometric coherence, interferometric repeat-pass data, polarimetric descriptors, RFI Suppression, sensitive parameters estimation, synthetic aperture radar imaging.
    Abstract: Radio interferences are becoming more and more an important source for image degradation in synthetic aperture radar (SAR) imaging. Especially at longer wavelengths, interferences are often very strong, and their suppression is required during data processing. However, at shorter wavelengths, interferences are often not obvious in the image amplitude, and filtering is not performed in an operational way. Nevertheless, interferences might significantly degrade the image phase, and the estimation of sensitive parameters like interferometric coherence or polarimetric descriptors becomes imprecise. Interference suppression is usually performed on the raw data, which are in most cases not available to the end-user. In this letter, a new interference suppression method for focused SAR images is proposed. Its performance is tested on interferometric repeat-pass data acquired by the German Aerospace Agency's experimental SAR system (E-SAR) at L-band.

    @Article{reigberFerrofamil2005:RFISuppInSLC,
    Title = {Interference suppression in synthesized SAR images},
    Author = {Reigber, A. and Ferro-Famil, L.},
    Number = {1},
    Pages = {45--49},
    Url = {http://ieeexplore.ieee.org/iel5/8859/30115/01381346.pdf},
    Volume = {2},
    Year = {2005},
    Abstract = {Radio interferences are becoming more and more an important source for image degradation in synthetic aperture radar (SAR) imaging. Especially at longer wavelengths, interferences are often very strong, and their suppression is required during data processing. However, at shorter wavelengths, interferences are often not obvious in the image amplitude, and filtering is not performed in an operational way. Nevertheless, interferences might significantly degrade the image phase, and the estimation of sensitive parameters like interferometric coherence or polarimetric descriptors becomes imprecise. Interference suppression is usually performed on the raw data, which are in most cases not available to the end-user. In this letter, a new interference suppression method for focused SAR images is proposed. Its performance is tested on interferometric repeat-pass data acquired by the German Aerospace Agency's experimental SAR system (E-SAR) at L-band.},
    Journal = {IEEE Geosci. Remote Sens. Lett.},
    Keywords = {SAR Processsing, filtering theory, interference suppression, radar imaging, radar interference, synthetic aperture radar, German Aerospace Agency, L-Band, ESAR, SAR imaging, data processing, experimental SAR system, filtering theory, focused SAR images, SLC, image degradation, interferometric coherence, interferometric repeat-pass data, polarimetric descriptors, RFI Suppression, sensitive parameters estimation, synthetic aperture radar imaging},
    Owner = {ofrey},
    Pdf = {../../../docs/reigberFerrofamil2005.pdf} 
    }
    


  20. Brian D. Rigling and Randolph L. Moses. Taylor expansion of the differential range for monostatic SAR. Aerospace and Electronic Systems, IEEE Transactions on, 41(1):60-64, 2005. Keyword(s): SAR Processing, polynomial approximation, radar imaging, synthetic aperture radar, Taylor expansion, differential range, linear approximation, monostatic SAR, Polar Format Algorithm, second-order Taylor series approximation, Spotlight SAR.
    Abstract: The polar format algorithm (PFA) for spotlight synthetic aperture radar (SAR) is based on a linear approximation for the differential range to a scatterer. We derive a second-order Taylor series approximation of the differential range. We provide a simple and concise derivation of both the far-field linear approximation of the differential range, which forms the basis of the PFA, and the corresponding approximation limits based on the second-order terms of the approximation.

    @Article{riglingMoses05:diffRange,
    Title = {Taylor expansion of the differential range for monostatic SAR},
    Author = {Rigling, Brian D. and Moses, Randolph L.},
    Number = {1},
    Pages = {60--64},
    Url = {http://ieeexplore.ieee.org/iel5/7/30637/01413746.pdf},
    Volume = {41},
    Year = {2005},
    Abstract = {The polar format algorithm (PFA) for spotlight synthetic aperture radar (SAR) is based on a linear approximation for the differential range to a scatterer. We derive a second-order Taylor series approximation of the differential range. We provide a simple and concise derivation of both the far-field linear approximation of the differential range, which forms the basis of the PFA, and the corresponding approximation limits based on the second-order terms of the approximation.},
    Journal = {Aerospace and Electronic Systems, IEEE Transactions on},
    Keywords = {SAR Processing, polynomial approximation, radar imaging, synthetic aperture radar, Taylor expansion, differential range, linear approximation, monostatic SAR, Polar Format Algorithm, second-order Taylor series approximation, Spotlight SAR},
    Owner = {ofrey},
    Pdf = {../../../docs/riglingMoses05.pdf} 
    }
    


  21. Petre Stoica, Zhisong Wang, and Jian Li. Extended derivations of MUSIC in the presence of steering vector errors. IEEE Transactions on Signal Processing, 53(3):1209-1211, March 2005. Keyword(s): SAR Processing, MUSIC, MUltiple SIgnal Classifier, direction-of-arrival estimation, DOA, robustness to steering vector errors, extended derivation, steering vector error, SAR Tomography, Tomography, multi-baseline SAR, InSAR.
    Abstract: We present two extensions of MUSIC to the case in which the steering vector is imprecisely known and show that the extended methods lead to the same direction-of-arrival (DOA) estimates as MUSIC. This somewhat surprising result provides a more general motivation of MUSIC than those currently available and shows that MUSIC possesses a certain degree of inherent robustness to steering vector errors.

    @Article{stoicaWangLi2005:musicDOARobust,
    Title = {Extended derivations of {MUSIC} in the presence of steering vector errors},
    Author = {Stoica, Petre and Zhisong Wang and Jian Li},
    Doi = {10.1109/TSP.2004.842201},
    ISSN = {1053-587X},
    Month = mar,
    Number = {3},
    Pages = {1209-1211},
    Url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1396448},
    Volume = {53},
    Year = {2005},
    Abstract = {We present two extensions of MUSIC to the case in which the steering vector is imprecisely known and show that the extended methods lead to the same direction-of-arrival (DOA) estimates as MUSIC. This somewhat surprising result provides a more general motivation of MUSIC than those currently available and shows that MUSIC possesses a certain degree of inherent robustness to steering vector errors.},
    Journal = {IEEE Transactions on Signal Processing},
    Keywords = {SAR Processing, MUSIC, MUltiple SIgnal Classifier, direction-of-arrival estimation, DOA, robustness to steering vector errors, extended derivation, steering vector error, SAR Tomography, Tomography, multi-baseline SAR, InSAR},
    Owner = {ofrey},
    Pdf = {../../../docs/stoicaWangLi2005.pdf} 
    }
    


  22. Tazio Strozzi, Paolo Farina, Alessandro Corsini, Christian Ambrosi, Manfred Thüring, Johannes Zilger, Andreas Wiesmann, Urs Wegmuller, and Charles L. Werner. Survey and monitoring of landslide displacements by means of L-band satellite SAR interferometry. Landslides, 2(3):193-201, 2005. Keyword(s): SAR Processing, PSI, Persistent Scatterer Interferometry, Landslides, Displacement, Landslide displacement investigation, SAR interferometry, L-band, Swiss and Italian Alps.
    Abstract: This paper illustrates the capabilities of L-band satellite SAR interferometry for the investigation of landslide displacements. SAR data acquired by the L-band JERS satellite over the Italian and Swiss Alps have been analyzed together with C-band ERS-1/2 SAR data and in situ information. The use of L-band SAR data with a wavelength larger than the usual C-band, generally considered for ground motion measurements, reduces some of the limitations of differential SAR interferometry, in particular, signal decorrelation induced by vegetation cover and rapid displacements. The sites of the Alta Val Badia region in South Tyrol (Italy), Ruinon in Lombardia (Italy), Saas Grund in Valais (Switzerland) and Campo Vallemaggia in Ticino (Switzerland), representing a comprehensive set of different mass wasting phenomena in various environments, are considered. The landslides in the Alta Val Badia region are good examples for presenting the improved performance of L-band in comparison to C-band for vegetated areas, in particular concerning open forest. The landslides of Ruinon, Saas Grund, and Campo Vallemaggia demonstrate the strength of L-band in observing moderately fast displacements in comparison to C-band. This work, performed with historical SAR data from a satellite which operated until 1998, demonstrates the capabilities of future planned L-band SAR missions, like ALOS and TerraSAR-L, for landslide studies.

    @Article{strozziEtAlLandslidesJERS2005,
    author = {Strozzi, Tazio and Farina, Paolo and Corsini, Alessandro and Ambrosi, Christian and Th\"uring, Manfred and Zilger, Johannes and Wiesmann, Andreas and Wegmuller, Urs and Werner, Charles L.},
    title = {Survey and monitoring of landslide displacements by means of {L-band} satellite {SAR} interferometry},
    journal = {Landslides},
    year = {2005},
    volume = {2},
    number = {3},
    pages = {193-201},
    issn = {1612-510X},
    abstract = {This paper illustrates the capabilities of L-band satellite SAR interferometry for the investigation of landslide displacements. SAR data acquired by the L-band JERS satellite over the Italian and Swiss Alps have been analyzed together with C-band ERS-1/2 SAR data and in situ information. The use of L-band SAR data with a wavelength larger than the usual C-band, generally considered for ground motion measurements, reduces some of the limitations of differential SAR interferometry, in particular, signal decorrelation induced by vegetation cover and rapid displacements. The sites of the Alta Val Badia region in South Tyrol (Italy), Ruinon in Lombardia (Italy), Saas Grund in Valais (Switzerland) and Campo Vallemaggia in Ticino (Switzerland), representing a comprehensive set of different mass wasting phenomena in various environments, are considered. The landslides in the Alta Val Badia region are good examples for presenting the improved performance of L-band in comparison to C-band for vegetated areas, in particular concerning open forest. The landslides of Ruinon, Saas Grund, and Campo Vallemaggia demonstrate the strength of L-band in observing moderately fast displacements in comparison to C-band. This work, performed with historical SAR data from a satellite which operated until 1998, demonstrates the capabilities of future planned L-band SAR missions, like ALOS and TerraSAR-L, for landslide studies.},
    doi = {10.1007/s10346-005-0003-2},
    file = {:strozziEtAlLandslidesJERS2005.pdf:PDF},
    keywords = {SAR Processing, PSI, Persistent Scatterer Interferometry, Landslides, Displacement, Landslide displacement investigation; SAR interferometry; L-band; Swiss and Italian Alps},
    pdf = {../../../docs/strozziEtAlLandslidesJERS2005.pdf},
    publisher = {Springer-Verlag},
    url = {http://dx.doi.org/10.1007/s10346-005-0003-2},
    
    }
    


  23. Y. Yamaguchi, T. Moriyama, M. Ishido, and H. Yamada. Four-component scattering model for polarimetric SAR image decomposition. IEEE Trans. Geosci. Remote Sens., 43(8):1699-1706, August 2005. Keyword(s): SAR Processing, polarimetric decomposition, Yamaguchi decomposition, asymmetric covariance matrix, cloud, co-pol correlation, cross-pol correlation, dipole scatterers, double bounce scattering, four-component scattering model, helix scattering power, image decomposition, nonreflection symmetric scattering, polarimetric SAR, probability density function, radar polarimetry, reflection symmetry condition, scattering contribution decomposition, surface scattering, symmetric covariance matrix, synthetic aperture radar, three-component decomposition method, urban area scattering, volume scattering, covariance matrices, geophysical signal processing, probability, radar polarimetry, remote sensing by radar, synthetic aperture radar.
    Abstract: A four-component scattering model is proposed to decompose polarimetric synthetic aperture radar (SAR) images. The covariance matrix approach is used to deal with the nonreflection symmetric scattering case. This scheme includes and extends the three-component decomposition method introduced by Freeman and Durden dealing with the reflection symmetry condition that the co-pol and the cross-pol correlations are close to zero. Helix scattering power is added as the fourth component to the three-component scattering model which describes surface, double bounce, and volume scattering. This helix scattering term is added to take account of the co-pol and the cross-pol correlations which generally appear in complex urban area scattering and disappear for a natural distributed scatterer. This term is relevant for describing man-made targets in urban area scattering. In addition, asymmetric volume scattering covariance matrices are introduced in dependence of the relative backscattering magnitude between HH and VV. A modification of probability density function for a cloud of dipole scatterers yields asymmetric covariance matrices. An appropriate choice among the symmetric or asymmetric volume scattering covariance matrices allows us to make a best fit to the measured data. A four-component decomposition algorithm is developed to deal with a general scattering case. The result of this decomposition is demonstrated with L-band Pi-SAR images taken over the city of Niigata, Japan.

    @Article{yamaguchiMoriyamaIshidoYamada2005:PolDecomp,
    Title = {Four-component scattering model for polarimetric {SAR} image decomposition},
    Author = {Yamaguchi, Y. and Moriyama, T. and Ishido, M. and Yamada, H.},
    Doi = {10.1109/TGRS.2005.852084},
    ISSN = {0196-2892},
    Month = aug,
    Number = {8},
    Pages = {1699-1706},
    Volume = {43},
    Year = {2005},
    Abstract = {A four-component scattering model is proposed to decompose polarimetric synthetic aperture radar (SAR) images. The covariance matrix approach is used to deal with the nonreflection symmetric scattering case. This scheme includes and extends the three-component decomposition method introduced by Freeman and Durden dealing with the reflection symmetry condition that the co-pol and the cross-pol correlations are close to zero. Helix scattering power is added as the fourth component to the three-component scattering model which describes surface, double bounce, and volume scattering. This helix scattering term is added to take account of the co-pol and the cross-pol correlations which generally appear in complex urban area scattering and disappear for a natural distributed scatterer. This term is relevant for describing man-made targets in urban area scattering. In addition, asymmetric volume scattering covariance matrices are introduced in dependence of the relative backscattering magnitude between HH and VV. A modification of probability density function for a cloud of dipole scatterers yields asymmetric covariance matrices. An appropriate choice among the symmetric or asymmetric volume scattering covariance matrices allows us to make a best fit to the measured data. A four-component decomposition algorithm is developed to deal with a general scattering case. The result of this decomposition is demonstrated with L-band Pi-SAR images taken over the city of Niigata, Japan.},
    Journal = {IEEE Trans. Geosci. Remote Sens.},
    Keywords = {SAR Processing, polarimetric decomposition, Yamaguchi decomposition, asymmetric covariance matrix; cloud; co-pol correlation; cross-pol correlation; dipole scatterers; double bounce scattering; four-component scattering model; helix scattering power; image decomposition; nonreflection symmetric scattering; polarimetric SAR; probability density function; radar polarimetry; reflection symmetry condition; scattering contribution decomposition; surface scattering; symmetric covariance matrix; synthetic aperture radar; three-component decomposition method; urban area scattering; volume scattering; covariance matrices; geophysical signal processing; probability; radar polarimetry; remote sensing by radar; synthetic aperture radar},
    Pdf = {../../../docs/yamaguchiMoriyamaIshidoYamada2005.pdf} 
    }
    


Conference articles

  1. M. Blom and P. Follo. VHF SAR image formation implemented on a GPU. In IEEE International Geoscience and Remote Sensing Symposium, IGARSS '05., volume 5, pages 3352-3356, July 2005. Keyword(s): SAR Processing, Time-Domain Back-Projection, TDBP, GPU, Graphic Processing Unit, GPU Processing, 3D Graphics Card, VHF, Airborne SAR, FOI, CARABAS.
    Abstract: This paper will describe how off-the-shelf 3D graphics cards can be used for scientific computation like SAR processing. In particular, a highly efficient one-dimensional FFT and a fast direct (global) backprojection implementation will be presented and analyzed.

    @InProceedings{blomFollo2005:TDPBonGPU,
    author = {Blom, M. and Follo, P.},
    booktitle = {IEEE International Geoscience and Remote Sensing Symposium, IGARSS '05.},
    title = {{VHF SAR image formation implemented on a GPU}},
    year = {2005},
    month = {July},
    pages = {3352-3356},
    volume = {5},
    abstract = {This paper will describe how off-the-shelf 3D graphics cards can be used for scientific computation like SAR processing. In particular, a highly efficient one-dimensional FFT and a fast direct (global) backprojection implementation will be presented and analyzed.},
    keywords = {SAR Processing, Time-Domain Back-Projection, TDBP, GPU, Graphic Processing Unit, GPU Processing, 3D Graphics Card, VHF, Airborne SAR, FOI, CARABAS},
    owner = {ofrey},
    pdf = {../../../docs/blomFollo2005.pdf},
    url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1526560&isnumber=32599},
    
    }
    


  2. F. Bordoni, A. Jakobsson, F. Gini, and F. Lombardini. On the Effects of Nonuniform Sampling for Interferometric Phase Estimation in the Presence of Layover. In Statistical Signal Processing, 2005 IEEE/SP 13th Workshop on, pages 645-650, July 2005.
    @InProceedings{Bordoni2005,
    Title = {On the Effects of Nonuniform Sampling for Interferometric Phase Estimation in the Presence of Layover},
    Author = {Bordoni, F. and Jakobsson, A. and Gini, F. and Lombardini, F.},
    Booktitle = {Statistical Signal Processing, 2005 IEEE/SP 13th Workshop on},
    Month = jul,
    Pages = {645--650},
    Year = {2005},
    Owner = {ofrey} 
    }
    


  3. Karlus A. Câmara de Macedo, Christian Andres, and Rolf Scheiber. On the requirements of SAR processing for airborne differential interferometry. In Proc. IEEE Int. Geosci. Remote Sens. Symp., volume 4, pages 2693-2696, July 2005. Keyword(s): SAR Processing, PTA-MoComp, Postprocessing, Motion Compensation, Topography-Based Motion Compensation, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm, fast Fourier transform-based postprocessing methodology, FFT, D-InSAR, German Aerospace Center, DLR, airborne repeat-pass interferometry, differential interferometry, geometric fidelity, motion errors, phase accuracy, residual phase errors, topographic heights, Topography, DEM, Terrain, wide beamwidth, Airborne SAR, ESAR.
    Abstract: Airborne Differential SAR Interferometry (DInSAR) is still a challenging task when compared to the spaceborne case due to the fact that airborne platforms are unable to describe a stable flight track. For that reason a very precise motion compensation which includes the correction of topographic-induced phase errors has to be performed in the airborne SAR data. This paper presents the required steps of phase correction to achieve accurate airborne D-InSAR data. The latest airborne D-InSAR processing chain of the E-SAR system is shown. Differential interferograms results using the proposed processing chain are also shown.

    @InProceedings{macedoAndresScheiber2005:DInSAR,
    Title = {{On the requirements of {SAR} processing for airborne differential interferometry}},
    Author = {C\^amara de Macedo, Karlus A. and Andres, Christian and Scheiber, Rolf},
    Booktitle = {Proc. IEEE Int. Geosci. Remote Sens. Symp.},
    Month = jul,
    Pages = {2693--2696},
    Url = {http://ieeexplore.ieee.org/iel5/10226/32598/01525621.pdf},
    Volume = {4},
    Year = {2005},
    Abstract = {Airborne Differential SAR Interferometry (DInSAR) is still a challenging task when compared to the spaceborne case due to the fact that airborne platforms are unable to describe a stable flight track. For that reason a very precise motion compensation which includes the correction of topographic-induced phase errors has to be performed in the airborne SAR data. This paper presents the required steps of phase correction to achieve accurate airborne D-InSAR data. The latest airborne D-InSAR processing chain of the E-SAR system is shown. Differential interferograms results using the proposed processing chain are also shown.},
    Keywords = {SAR Processing, PTA-MoComp, Postprocessing, Motion Compensation, Topography-Based Motion Compensation, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm, fast Fourier transform-based postprocessing methodology, FFT, D-InSAR, German Aerospace Center, DLR, airborne repeat-pass interferometry, differential interferometry, geometric fidelity, motion errors, phase accuracy, residual phase errors, topographic heights, Topography, DEM, Terrain, wide beamwidth, Airborne SAR, ESAR},
    Owner = {ofrey},
    Pdf = {../../../docs/macedoAndresScheiber2005.pdf} 
    }
    


  4. Armin W. Doerry. Autofocus correction of SAR images exhibiting excessive residual migration. In Robert N. Trebits and James L. Kurtz, editors, Proceedings of SPIE Vol. 5788, Radar Sensor Technology IX, volume 5788, pages 34-45, 2005. SPIE. Keyword(s): SAR Processing, Autofocus, Phase Gradient Autofocus.
    Abstract: Relatively small motion measurement errors manifest themselves principally as a phase error in Synthetic Aperture Radar (SAR) complex data samples, and if large enough become observable as a smearing, blurring, or other degradation in the image. The phase error function can be measured and then deconvolved from the original data to compensate for the presumed motion error, ultimately resulting in a well-focused image. Techniques that do this are termed ?autofocus? algorithms. A very popular autofocus algorithm is the Phase Gradient Autofocus (PGA) algorithm. The nearly universal, and typically reasonable, assumption is that the motion errors are less than the range resolution of the radar, allowing solely a phase correction to suffice. Very large relative motion measurement errors manifest themselves as an unexpected additional shifting or migration of target locations beyond any deterministic migration during the course of the synthetic aperture. Degradation in images from data exhibiting errors of this magnitude are substantial, often rendering the image completely useless. When residual range migration due to either real or apparent motion errors exceeds the range resolution, conventional autofocus algorithms fail. Excessive residual migration is increasingly encountered as resolutions become finer, less expensive inertial sensors are used, and operating ranges become longer (due to atmospheric phenomena). A new migration-correction autofocus algorithm has been developed that estimates the excessive residual migration and applies phase and frequency corrections to properly focus the image. This overcomes the conventional constraint that motion errors not exceed the SAR range resolution.

    @InProceedings{Doerry2005Autofocus,
    author = {Armin W. Doerry},
    booktitle = {Proceedings of SPIE Vol. 5788, Radar Sensor Technology IX},
    title = {Autofocus correction of {SAR} images exhibiting excessive residual migration},
    year = {2005},
    editor = {Robert N. Trebits and James L. Kurtz},
    number = {1},
    pages = {34-45},
    publisher = {SPIE},
    volume = {5788},
    abstract = {Relatively small motion measurement errors manifest themselves principally as a phase error in Synthetic Aperture Radar (SAR) complex data samples, and if large enough become observable as a smearing, blurring, or other degradation in the image. The phase error function can be measured and then deconvolved from the original data to compensate for the presumed motion error, ultimately resulting in a well-focused image. Techniques that do this are termed ?autofocus? algorithms. A very popular autofocus algorithm is the Phase Gradient Autofocus (PGA) algorithm. The nearly universal, and typically reasonable, assumption is that the motion errors are less than the range resolution of the radar, allowing solely a phase correction to suffice. Very large relative motion measurement errors manifest themselves as an unexpected additional shifting or migration of target locations beyond any deterministic migration during the course of the synthetic aperture. Degradation in images from data exhibiting errors of this magnitude are substantial, often rendering the image completely useless. When residual range migration due to either real or apparent motion errors exceeds the range resolution, conventional autofocus algorithms fail. Excessive residual migration is increasingly encountered as resolutions become finer, less expensive inertial sensors are used, and operating ranges become longer (due to atmospheric phenomena). A new migration-correction autofocus algorithm has been developed that estimates the excessive residual migration and applies phase and frequency corrections to properly focus the image. This overcomes the conventional constraint that motion errors not exceed the SAR range resolution.},
    file = {:Doerry2005Autofocus.pdf:PDF},
    keywords = {SAR Processing, Autofocus, Phase Gradient Autofocus},
    location = {Orlando, FL, USA},
    pdf = {../../../docs/Doerry2005Autofocus.pdf},
    url = {http://link.aip.org/link/?PSI/5788/34/1},
    
    }
    


  5. Armin W. Doerry, Dale F. Dubbert, Martin Thompson, and Vivian D. Gutierrez. A portfolio of fine resolution Ka-band SAR images: part I. In Robert N. Trebits and James L. Kurtz, editors, Proc. of SPIE Vol. 5788, Radar Sensor Technology IX, number 1, pages 13-24, 2005. SPIE. Keyword(s): SAR Processing, High Resolution, Fine Resolution, Sandia National Laboratoiries, Ka-Band.
    Abstract: Sandia National Laboratories designs and builds Synthetic Aperture Radar (SAR) systems capable of forming highquality exceptionally fine resolution images. During the spring of 2004 a series of test flights were completed with a Ka-band testbed SAR on Sandia?s DeHavilland DHC-6 Twin Otter aircraft. A large data set was collected including real-time fine-resolution images of a variety of target scenes. This paper offers a sampling of high quality images representative of the output of Sandia?s Ka-band testbed radar with resolutions as fine as 4 inches. Images will be annotated with descriptions of collection geometries and other relevant image parameters.

    @InProceedings{DoerryDubbertThompsonGutierrez2005:PartOne,
    Title = {A portfolio of fine resolution Ka-band SAR images: part I},
    Author = {Armin W. Doerry and Dale F. Dubbert and Martin Thompson and Vivian D. Gutierrez},
    Booktitle = {Proc. of SPIE Vol. 5788, Radar Sensor Technology IX},
    Editor = {Robert N. Trebits and James L. Kurtz},
    Location = {Orlando, FL, USA},
    Number = {1},
    Pages = {13-24},
    Publisher = {SPIE},
    Url = {http://link.aip.org/link/?PSI/5788/13/1},
    Year = {2005},
    Abstract = {Sandia National Laboratories designs and builds Synthetic Aperture Radar (SAR) systems capable of forming highquality exceptionally fine resolution images. During the spring of 2004 a series of test flights were completed with a Ka-band testbed SAR on Sandia?s DeHavilland DHC-6 Twin Otter aircraft. A large data set was collected including real-time fine-resolution images of a variety of target scenes. This paper offers a sampling of high quality images representative of the output of Sandia?s Ka-band testbed radar with resolutions as fine as 4 inches. Images will be annotated with descriptions of collection geometries and other relevant image parameters.},
    Keywords = {SAR Processing, High Resolution, Fine Resolution, Sandia National Laboratoiries, Ka-Band},
    Owner = {ofrey},
    Pdf = {../../../docs/DoerryDubbertThompsonGutierrezPartOne2005.pdf} 
    }
    


  6. Armin W. Doerry, Dale F. Dubbert, Martin Thompson, and Vivian D. Gutierrez. A portfolio of fine resolution Ka-band SAR images: part II. In Robert N. Trebits and James L. Kurtz, editors, Proc. of SPIE Vol. 5788, Radar Sensor Technology IX, number 1, pages 185-196, 2005. SPIE. Keyword(s): SAR Processing, High Resolution, Fine Resolution, Sandia National Laboratoiries, Ka-Band.
    Abstract: Sandia National Laboratories designs and builds Synthetic Aperture Radar (SAR) systems capable of forming highquality exceptionally fine resolution images. During the spring of 2004 a series of test flights were completed with a Ka-band testbed SAR on Sandia?s DeHavilland DHC-6 Twin Otter aircraft. A large data set was collected including real-time fine-resolution images of a variety of target scenes. This paper offers a sampling of high quality images representative of the output of Sandia?s Ka-band testbed radar with resolutions as fine as 4 inches. Images will be annotated with descriptions of collection geometries and other relevant image parameters.

    @InProceedings{DoerryDubbertThompsonGutierrez2005:PartTwo,
    Title = {A portfolio of fine resolution Ka-band SAR images: part II},
    Author = {Armin W. Doerry and Dale F. Dubbert and Martin Thompson and Vivian D. Gutierrez},
    Booktitle = {Proc. of SPIE Vol. 5788, Radar Sensor Technology IX},
    Editor = {Robert N. Trebits and James L. Kurtz},
    Location = {Orlando, FL, USA},
    Number = {1},
    Pages = {185-196},
    Publisher = {SPIE},
    Url = {http://link.aip.org/link/?PSI/5788/185/1},
    Year = {2005},
    Abstract = {Sandia National Laboratories designs and builds Synthetic Aperture Radar (SAR) systems capable of forming highquality exceptionally fine resolution images. During the spring of 2004 a series of test flights were completed with a Ka-band testbed SAR on Sandia?s DeHavilland DHC-6 Twin Otter aircraft. A large data set was collected including real-time fine-resolution images of a variety of target scenes. This paper offers a sampling of high quality images representative of the output of Sandia?s Ka-band testbed radar with resolutions as fine as 4 inches. Images will be annotated with descriptions of collection geometries and other relevant image parameters.},
    Keywords = {SAR Processing, High Resolution, Fine Resolution, Sandia National Laboratoiries, Ka-Band},
    Owner = {ofrey},
    Pdf = {../../../docs/DoerryDubbertThompsonGutierrezPartTwo2005.pdf} 
    }
    


  7. Othmar Frey, Erich Meier, and Daniel Nüesch. A Study on Integrated SAR Processing and Geocoding by Means of Time-Domain Backprojection. In Proc. Int. Radar Symp., 2005. Keyword(s): SAR Processing, Time-Domain Back-Projection, Back-Projection, Geocoding, Radiometry, Calibration, Radiometric Calibration, ENVISAT/ASAR, Spaceborne SAR.
    Abstract: Geocoded products of synthetic aperture radar data are of great interest for many applications. The conventional processing chain, which leads to geographically referenced synthetic aperture data consists of two main steps: first, the raw data are focused and, in a second step, the resulting single look complex image is geocoded to the favoured coordinate system. We investigate a time-domain backprojection approach that replaces the two steps, focusing and geocoding, by one algorithm leading directly to terrain-geocoded images. The technique is evaluated with ENVISAT/ASAR image mode data. We assess the geolocation accuracy and the radiometric performance of dedicated point targets such as transponders and a corner reflector. In addition, we compare our findings with results from corresponding level 1 products processed at the European Space Agency (ESA), which were validated within the scope of ENVISAT/ASAR Cal/Val activities.

    @InProceedings{freyMeierNueschIRS05:StudyIntegratedBackproj,
    author = {Othmar Frey and Erich Meier and Daniel N{\"u}esch},
    title = {{A Study on Integrated SAR Processing and Geocoding by Means of Time-Domain Backprojection}},
    booktitle = {Proc. Int. Radar Symp.},
    year = {2005},
    abstract = {Geocoded products of synthetic aperture radar data are of great interest for many applications. The conventional processing chain, which leads to geographically referenced synthetic aperture data consists of two main steps: first, the raw data are focused and, in a second step, the resulting single look complex image is geocoded to the favoured coordinate system. We investigate a time-domain backprojection approach that replaces the two steps, focusing and geocoding, by one algorithm leading directly to terrain-geocoded images. The technique is evaluated with ENVISAT/ASAR image mode data. We assess the geolocation accuracy and the radiometric performance of dedicated point targets such as transponders and a corner reflector. In addition, we compare our findings with results from corresponding level 1 products processed at the European Space Agency (ESA), which were validated within the scope of ENVISAT/ASAR Cal/Val activities.},
    file = {:234_FreyMeierNuesch_IRS2005.pdf:PDF},
    keywords = {SAR Processing, Time-Domain Back-Projection, Back-Projection, Geocoding, Radiometry, Calibration, Radiometric Calibration, ENVISAT/ASAR, Spaceborne SAR},
    owner = {ofrey},
    pdf = {http://www.ifu-sar.ethz.ch/otfrey/SARbibliography/myPapers/234_FreyMeierNuesch_IRS2005.pdf},
    
    }
    


  8. Othmar Frey, Erich Meier, and Daniel Nüesch. Processing SAR data of rugged terrain by time-domain back-projection. In SPIE Vol. 5980: SAR Image Analysis, Modeling, and Techniques X, 2005. Keyword(s): SAR Processing, Time-Domain Back-Projection, Back-Projection, Terrain Correction, Radiometry, Radiometric Calibration, Radiometric Correction, Terrain, Topography, DEM Geocoding, ENVISAT/ASAR, Spaceborne SAR.
    Abstract: Processing of SAR images of rugged terrain deserves special care because the topography affects the focused image in a number of ways. In order to obtain geometrically and radiometrically corrected SAR images of mountainous areas additional knowledge about the topography and the sensor's trajectory and attitude has to be included in the processing or post-processing steps. Various well-known focusing techniques are available to transform SAR raw data into a single look complex image such as the range-Doppler, the chirp scaling or the omega-k algorithm. While these algorithms perform the azimuth focusing step in the frequency domain the time-domain back-projection processing technique focuses the data geometrically, i.e., in the time domain. In contrast to the frequency-domain techniques, time-domain back-projection maintains the entire geometric relationship between the sensor and the illuminated area. This implies a couple of advantages: a stringent, terrain-based correction for the elevation antenna gain pattern may be implemented and topography-induced variation of radar brightness can be eliminated in a single step. Further, the SAR image is focused directly onto an arbitrary reconstruction grid and in the desired geodetic reference frame without requiring any additional processing steps. We discuss the influence of rugged terrain on the radiometric properties of focused SAR data and demonstrate how the time-domain back-projection approach accounts for these effects within one integrated processing framework by incorporating both a correction for terrain slope induced variation of radar brightness and a stringent correction for the elevation antenna gain pattern. The algorithm is evaluated for ENVISAT/ASAR image mode data of a mountainous area.

    @InProceedings{freyMeierNueeschSPIE2005:Backprojection,
    author = {Othmar Frey and Erich Meier and Daniel N{\"u}esch},
    title = {Processing {SAR} data of rugged terrain by time-domain back-projection},
    booktitle = {SPIE Vol. 5980: SAR Image Analysis, Modeling, and Techniques X},
    year = {2005},
    abstract = {Processing of SAR images of rugged terrain deserves special care because the topography affects the focused image in a number of ways. In order to obtain geometrically and radiometrically corrected SAR images of mountainous areas additional knowledge about the topography and the sensor's trajectory and attitude has to be included in the processing or post-processing steps. Various well-known focusing techniques are available to transform SAR raw data into a single look complex image such as the range-Doppler, the chirp scaling or the omega-k algorithm. While these algorithms perform the azimuth focusing step in the frequency domain the time-domain back-projection processing technique focuses the data geometrically, i.e., in the time domain. In contrast to the frequency-domain techniques, time-domain back-projection maintains the entire geometric relationship between the sensor and the illuminated area. This implies a couple of advantages: a stringent, terrain-based correction for the elevation antenna gain pattern may be implemented and topography-induced variation of radar brightness can be eliminated in a single step. Further, the SAR image is focused directly onto an arbitrary reconstruction grid and in the desired geodetic reference frame without requiring any additional processing steps. We discuss the influence of rugged terrain on the radiometric properties of focused SAR data and demonstrate how the time-domain back-projection approach accounts for these effects within one integrated processing framework by incorporating both a correction for terrain slope induced variation of radar brightness and a stringent correction for the elevation antenna gain pattern. The algorithm is evaluated for ENVISAT/ASAR image mode data of a mountainous area.},
    doi = {10.1117/12.627647},
    file = {:FreyMeierNueesch_SPIE2005.pdf:PDF},
    keywords = {SAR Processing, Time-Domain Back-Projection, Back-Projection, Terrain Correction, Radiometry, Radiometric Calibration, Radiometric Correction, Terrain, Topography, DEM Geocoding, ENVISAT/ASAR, Spaceborne SAR},
    owner = {ofrey},
    pdf = {http://www.ifu-sar.ethz.ch/otfrey/SARbibliography/myPapers/FreyMeierNueesch_SPIE2005.pdf},
    
    }
    


  9. U. Gebhardt, Ottmar Loffeld, H. Nies, S. Knedlik, and Joachim H. G. Ender. Bistatic airborne/spaceborne hybrid experiment: basic considerations. In Roland Meynart, Steven P. Neeck, and Haruhisa Shimoda, editors, Proc. of SPIE Vol.5978, Sensors, Systems, and Next-Generation Satellites IX, number 1, 2005. SPIE. Keyword(s): SAR Processing, Bistatic SAR, Hybrid Bistatic SAR, Bistatic Airborne/Spaceborne SAR, Airborne SAR, Spaceborne SAR, Hybrid, Spotlight Mode, Sliding Spotlight Mode, Simulation, TerraSAR-X.
    Abstract: Collecting data using different sensors mounted on different platforms is the challenge of multisensorics. Applications in Synthetic Aperture Radar (SAR) normally lead to extreme bi- or multistatic constellations in the multisensorial case. This paper describes basic considerations concerning the geometry, especially the antenna steering for a bistatic SAR experiment. Using the TerraSAR-X as a transmitter and a SAR system mounted on a plane as a receiver we want to record experimental raw data for further processing. Because of the high difference between the velocity of the transmitter platform and that of the receiver platform relative to a point target, stripmap mode is not useful in this case. By operating the transmitter in sliding spotlight or spotlight mode and using antenna steering to provide footprint chasing on the side of the receiving system, a useful scene extension in azimuth can be achieved. This is of course at the cost of a shorter time interval in which the point target is both illuminated by the transmitter and seen by the receiver. First simulations of a point target response will show that nevertheless we can expect a useful Doppler bandwidth and thus an adequate resolution in azimuth.

    @InProceedings{GebhardtLoffeldNiesKnedlikEnder2005,
    author = {U. Gebhardt and Ottmar Loffeld and H. Nies and S. Knedlik and Joachim H. G. Ender},
    title = {Bistatic airborne/spaceborne hybrid experiment: basic considerations},
    booktitle = {Proc. of SPIE Vol.5978, Sensors, Systems, and Next-Generation Satellites IX},
    year = {2005},
    editor = {Roland Meynart and Steven P. Neeck and Haruhisa Shimoda},
    number = {1},
    publisher = {SPIE},
    abstract = {Collecting data using different sensors mounted on different platforms is the challenge of multisensorics. Applications in Synthetic Aperture Radar (SAR) normally lead to extreme bi- or multistatic constellations in the multisensorial case. This paper describes basic considerations concerning the geometry, especially the antenna steering for a bistatic SAR experiment. Using the TerraSAR-X as a transmitter and a SAR system mounted on a plane as a receiver we want to record experimental raw data for further processing. Because of the high difference between the velocity of the transmitter platform and that of the receiver platform relative to a point target, stripmap mode is not useful in this case. By operating the transmitter in sliding spotlight or spotlight mode and using antenna steering to provide footprint chasing on the side of the receiving system, a useful scene extension in azimuth can be achieved. This is of course at the cost of a shorter time interval in which the point target is both illuminated by the transmitter and seen by the receiver. First simulations of a point target response will show that nevertheless we can expect a useful Doppler bandwidth and thus an adequate resolution in azimuth.},
    file = {:GebhardtLoffeldNiesKnedlikEnder2005.pdf:PDF},
    keywords = {SAR Processing, Bistatic SAR, Hybrid Bistatic SAR, Bistatic Airborne/Spaceborne SAR, Airborne SAR, Spaceborne SAR, Hybrid, Spotlight Mode, Sliding Spotlight Mode, Simulation, TerraSAR-X},
    location = {Brugge, Belgium},
    numpages = {10},
    owner = {ofrey},
    pdf = {../../../docs/GebhardtLoffeldNiesKnedlikEnder2005.pdf},
    url = {http://link.aip.org/link/?PSI/5978/59781M/1},
    
    }
    


  10. Stéphane Guillaso and Andreas Reigber. Polarimetric SAR Tomography (POLTOMSAR). In Proceedings of POLINSAR'05, Frascati, Italy, 2005. Keyword(s): SAR Processing, SAR Tomography, Tomography, MUSIC, Beamforming, Capon, Modified MUSIC, DoA, Direction of Arrival, Fourier, Pol-InSAR, L-Band, ESAR.
    Abstract: In this paper, different approaches of airborne SAR tomography are presented. A SAR tomographic data acquisition system can be represented like an antenna array. The use of high-resolution methods is indicated to the concept of aperture synthesis for 3D-imaging using SAR data. Techniques presented are the standard Fourier-, Capon-based beamforming methods to improve the resolution quality. In order to estimate the nature of retrieved target, a polarimetric approach is introduced based on the modified high-resolution MUSIC algorithm. Finally, experimental results are shown using a multibaseline data set acquired in L-band by DLR?s experimental SAR (E-SAR) on a test site near Oberpfaffenhofen / Germany.

    @InProceedings{guillasoReigber05:TomoSAR,
    Title = {{Polarimetric SAR Tomography (POLTOMSAR)}},
    Author = {St\'ephane Guillaso and Andreas Reigber},
    Booktitle = {Proceedings of POLINSAR'05},
    Year = {2005},
    Abstract = {In this paper, different approaches of airborne SAR tomography are presented. A SAR tomographic data acquisition system can be represented like an antenna array. The use of high-resolution methods is indicated to the concept of aperture synthesis for 3D-imaging using SAR data. Techniques presented are the standard Fourier-, Capon-based beamforming methods to improve the resolution quality. In order to estimate the nature of retrieved target, a polarimetric approach is introduced based on the modified high-resolution MUSIC algorithm. Finally, experimental results are shown using a multibaseline data set acquired in L-band by DLR?s experimental SAR (E-SAR) on a test site near Oberpfaffenhofen / Germany.},
    Address = {Frascati, Italy},
    Keywords = {SAR Processing, SAR Tomography, Tomography, MUSIC, Beamforming, Capon, Modified MUSIC, DoA, Direction of Arrival, Fourier, Pol-InSAR, L-Band,ESAR},
    Owner = {ofrey},
    Pdf = {../../../docs/guillasoReigber05PolInSAR.pdf} 
    }
    


  11. S. Guillaso and A. Reigber. Scatterer characterisation using polarimetric SAR tomography. In Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International, volume 4, pages 2685-2688, July 2005.
    @InProceedings{Guillaso2005a,
    Title = {Scatterer characterisation using polarimetric SAR tomography},
    Author = {Guillaso, S. and Reigber, A.},
    Booktitle = {Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International},
    Month = jul,
    Pages = {2685--2688},
    Volume = {4},
    Year = {2005},
    Owner = {ofrey},
    Timestamp = {2009.07.01} 
    }
    


  12. S. Guillaso, A. Reigber, and L. Ferro-Famil. Evaluation of the ESPRIT approach in polarimetric interferometric SAR. In Proc. Geosci. Remote Sens. Symp., volume 1, pages 1-4, 2005. Keyword(s): SAR Processing, SAR Tomography, Tomography, airborne radar, data acquisition, radar imaging, radar polarimetry, radiowave interferometry, remote sensing by radar, stereo image processing, synthetic aperture radar, tomography, vegetation mapping, 3D images, ESPRIT approach, German Aerospace Center, SAR tomography, airborne L-band repeat-pass interferometric data, data acquisition, experimental airborne SAR, polarimetric interferometric SAR, tomographic image, vegetation, volumetric area, E-SAR.
    Abstract: This paper presents a first evaluation of the ESPRIT approach in polarimetric interferometric SAR. This evaluation is carried out by using 3D images obtained by SAR tomographic like an alternative to the acquisition of ground-truth data, which is an extremely complex task in the case of volume areas. All parameters over a volumetric area are directly visible in a tomographic image and can, therefore, be employed to validate the ESPRIT approach by comparing parameters generated by ESPRIT and the SAR tomography approach. This allows to identify the principal deficiencies of the ESPRIT method, which occur over high vegetation areas, where there is a misinterpretation of the ESPRIT results. Whereas, the ESPRIT approach is useful for building characterisation, identifying a good applicability area. Airborne L-band repeat-pass interferometric data of the German Aerospace Center (DLR) experimental airborne SAR are used to perform this evaluation.

    @InProceedings{guillasoReigberFerroFamil05:Tomo,
    Title = {Evaluation of the {ESPRIT} approach in polarimetric interferometric {SAR}},
    Author = {Guillaso, S. and Reigber, A. and Ferro-Famil, L.},
    Booktitle = {Proc. Geosci. Remote Sens. Symp.},
    Pages = {1-4},
    Url = {http://ieeexplore.ieee.org/iel5/10226/32595/01526096.pdf},
    Volume = {1},
    Year = {2005},
    Abstract = {This paper presents a first evaluation of the ESPRIT approach in polarimetric interferometric SAR. This evaluation is carried out by using 3D images obtained by SAR tomographic like an alternative to the acquisition of ground-truth data, which is an extremely complex task in the case of volume areas. All parameters over a volumetric area are directly visible in a tomographic image and can, therefore, be employed to validate the ESPRIT approach by comparing parameters generated by ESPRIT and the SAR tomography approach. This allows to identify the principal deficiencies of the ESPRIT method, which occur over high vegetation areas, where there is a misinterpretation of the ESPRIT results. Whereas, the ESPRIT approach is useful for building characterisation, identifying a good applicability area. Airborne L-band repeat-pass interferometric data of the German Aerospace Center (DLR) experimental airborne SAR are used to perform this evaluation.},
    Keywords = {SAR Processing, SAR Tomography,Tomography, airborne radar, data acquisition, radar imaging, radar polarimetry, radiowave interferometry, remote sensing by radar, stereo image processing, synthetic aperture radar, tomography, vegetation mapping, 3D images, ESPRIT approach, German Aerospace Center, SAR tomography, airborne L-band repeat-pass interferometric data, data acquisition, experimental airborne SAR, polarimetric interferometric SAR, tomographic image, vegetation, volumetric area, E-SAR},
    Owner = {ofrey},
    Pdf = {../../../docs/guillasoReigberFerroFamilTomo05.pdf} 
    }
    


  13. T. Hamasaki, L. Ferro-Famil, E. Pottier, and M. Sato. Applications of polarimetric interferometric ground-based SAR (GB-SAR) system to environment monitoring and disaster prevention. In Proc. EURAD 2005. European Radar Conf, pages 29-32, October 2005. Keyword(s): GB-SAR, ground-based SAR, terrestrial SAR, disasters, environmental management, monitoring, radar polarimetry, radiowave interferometry, remote sensing by radar, synthetic aperture radar, coniferous tree, differential interferometry, disaster prevention, environment monitoring, natural phenomena, polarimetric interferometric ground-based SAR, resources management, scattering mechanisms, synthetic aperture radar, Aperture antennas, Frequency, Information analysis, Interferometry, Optical scattering, Radar detection, Radar scattering, Remote monitoring, Spaceborne radar, Synthetic aperture radar.
    @InProceedings{Hamasaki2005,
    author = {T. Hamasaki and L. Ferro-Famil and E. Pottier and M. Sato},
    title = {Applications of polarimetric interferometric ground-based {SAR} (GB-{SAR}) system to environment monitoring and disaster prevention},
    booktitle = {Proc. EURAD 2005. European Radar Conf},
    year = {2005},
    month = oct,
    pages = {29--32},
    doi = {10.1109/EURAD.2005.1605556},
    keywords = {GB-SAR,ground-based SAR, terrestrial SAR,disasters, environmental management, monitoring, radar polarimetry, radiowave interferometry, remote sensing by radar, synthetic aperture radar, coniferous tree, differential interferometry, disaster prevention, environment monitoring, natural phenomena, polarimetric interferometric ground-based SAR, resources management, scattering mechanisms, synthetic aperture radar, Aperture antennas, Frequency, Information analysis, Interferometry, Optical scattering, Radar detection, Radar scattering, Remote monitoring, Spaceborne radar, Synthetic aperture radar},
    owner = {ofrey},
    
    }
    


  14. J. Kolman. PACE: an autofocus algorithm for SAR. In Proc. IEEE Int. Radar Conference, pages 310-314, May 2005. Keyword(s): SAR Processing, Autofocus, Phase Adjustment by Contrast Enhancement, PACE, Azimuth, Focusing, Error correction, Synthetic aperture radar, Phase measurement, Pixel, Flexible printed circuits, Hardware, History, Error analysis.
    @InProceedings{kolmanIEEERadarCon2005PhaseAdjustmentByContrastEnhancementAutofocus,
    author = {J. {Kolman}},
    booktitle = {Proc. IEEE Int. Radar Conference},
    title = {{PACE}: an autofocus algorithm for {SAR}},
    year = {2005},
    month = may,
    pages = {310-314},
    doi = {10.1109/RADAR.2005.1435841},
    file = {:kolmanIEEERadarCon2005PhaseAdjustmentByContrastEnhancementAutofocus.pdf:PDF},
    issn = {2375-5318},
    keywords = {SAR Processing, Autofocus, Phase Adjustment by Contrast Enhancement, PACE,Azimuth;Focusing;Error correction;Synthetic aperture radar;Phase measurement;Pixel;Flexible printed circuits;Hardware;History;Error analysis},
    owner = {ofrey},
    
    }
    


  15. V. C. Koo, T. S. Lim, and H. T. Chuah. A Comparison of Autofocus Algorithms for SAR Imagery. In Progress In Electromagnetics Research Symposium, volume 1, Hangzhou, China, pages 16-9, 2005. Keyword(s): SAR Processing, Autofocus, Motion Compensation, MoComp, Residual Motion Errors, Comparion of Algorithms, Comparison of Autofocus Algorithms, Airborne SAR, Phase Gradient Autofocus, PGA, Eigenvector Method, Maximum Likelihood Estimation.
    Abstract: A challenge in SAR system development involves compensation for nonlinear motion errors of the sensor platform. The uncompensated along-track motions can cause a severe loss of geometry accuracy and degrade SAR image quality. Autofocus techniques improve image focus by removing a large part of phase errors present after conventional motion compensation. It refers to the computer-automated error estimation and subsequent removal of the phase errors. Many autofocus algorithms have been proposed over the years, ranging from quantitative measurement of residual errors to qualitative visual comparison. However, due to the fact that different data sets and motion errors were employed, it is difficult to perform comparative studies on various algorithms. This paper compares and discusses some practical autofocus algorithms by using a common data set. Standard focal quality metrics are defined to measure how well an image is focused. Their implementation schemes and performance are evaluated in the presence of various phase errors, which include polynomial-like, high frequency sinusoidal, and random phase noise.

    @InProceedings{kooLimChuah2005:AutofocusComparison,
    Title = {{A Comparison of Autofocus Algorithms for SAR Imagery}},
    Author = {Koo, V. C. and Lim, T. S. and Chuah, H. T.},
    Booktitle = {Progress In Electromagnetics Research Symposium},
    Pages = {16--9},
    Url = {http://piers.mit.edu/piersonline/pdf/Vol1No1Page16to19.pdf},
    Volume = {1},
    Year = {2005},
    Abstract = {A challenge in SAR system development involves compensation for nonlinear motion errors of the sensor platform. The uncompensated along-track motions can cause a severe loss of geometry accuracy and degrade SAR image quality. Autofocus techniques improve image focus by removing a large part of phase errors present after conventional motion compensation. It refers to the computer-automated error estimation and subsequent removal of the phase errors. Many autofocus algorithms have been proposed over the years, ranging from quantitative measurement of residual errors to qualitative visual comparison. However, due to the fact that different data sets and motion errors were employed, it is difficult to perform comparative studies on various algorithms. This paper compares and discusses some practical autofocus algorithms by using a common data set. Standard focal quality metrics are defined to measure how well an image is focused. Their implementation schemes and performance are evaluated in the presence of various phase errors, which include polynomial-like, high frequency sinusoidal, and random phase noise.},
    Address = {Hangzhou, China},
    Keywords = {SAR Processing, Autofocus, Motion Compensation, MoComp, Residual Motion Errors, Comparion of Algorithms, Comparison of Autofocus Algorithms, Airborne SAR, Phase Gradient Autofocus, PGA,Eigenvector Method, Maximum Likelihood Estimation},
    Pdf = {../../../docs/kooLimChuah2005.pdf} 
    }
    


  16. Shu Li and Ian Cumming. Improved beat frequency estimation in the MLBF Doppler ambiguity resolver. In Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International, volume 5, pages 3348-3351, 2005. Keyword(s): SAR Processing, Doppler Centroid Estimation, Doppler Ambiguity Resolver, DAR, MLBF, Multilook Beat Frequency, Improved Multilook Beat Frequency.
    Abstract: Among the current Doppler ambiguity resolvers, the Multi-Look Beat frequency (MLBF) algorithm proves to be the most reliable one, especially in high contrast areas. The existing MLBF algorithm uses FFTs to measure the central frequency of the beat signal but the estimation accuracy is limited by quantization errors. This paper proposes an improved method of estimating the beat frequency in the MLBF algorithm that is based on phase increments. In our work, we examined five established frequency estimators and found that the Iterative Linear Prediction (ILP) method has the best performance. The experimental results on RADARSAT-1 data show that the new MLBF algorithm using ILP can obtain the correct ambiguity number in a higher percentage of blocks and that the RMS error of the results is less than half that of the existing method.

    @InProceedings{liCumming2005:DopAmb,
    Title = {Improved beat frequency estimation in the MLBF Doppler ambiguity resolver},
    Author = {Li, Shu and Cumming, Ian},
    Booktitle = {Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International},
    Pages = {3348--3351},
    Url = {http://ieeexplore.ieee.org/iel5/10226/32599/01526559.pdf},
    Volume = {5},
    Year = {2005},
    Abstract = {Among the current Doppler ambiguity resolvers, the Multi-Look Beat frequency (MLBF) algorithm proves to be the most reliable one, especially in high contrast areas. The existing MLBF algorithm uses FFTs to measure the central frequency of the beat signal but the estimation accuracy is limited by quantization errors. This paper proposes an improved method of estimating the beat frequency in the MLBF algorithm that is based on phase increments. In our work, we examined five established frequency estimators and found that the Iterative Linear Prediction (ILP) method has the best performance. The experimental results on RADARSAT-1 data show that the new MLBF algorithm using ILP can obtain the correct ambiguity number in a higher percentage of blocks and that the RMS error of the results is less than half that of the existing method.},
    Keywords = {SAR Processing, Doppler Centroid Estimation, Doppler Ambiguity Resolver, DAR, MLBF, Multilook Beat Frequency, Improved Multilook Beat Frequency},
    Owner = {ofrey},
    Pdf = {../../../docs/liCumming2005.pdf} 
    }
    


  17. F. Lombardini. Analysis of non-gaussian speckle statistics in high-resolution SAR images. In Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International, volume 2, pages 1337-1340, July 2005.
    @InProceedings{Lombardini2005,
    Title = {Analysis of non-gaussian speckle statistics in high-resolution SAR images},
    Author = {Lombardini, F.},
    Booktitle = {Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International},
    Doi = {10.1109/IGARSS.2005.1525368},
    Month = jul,
    Pages = {1337--1340},
    Volume = {2},
    Year = {2005},
    Owner = {ofrey} 
    }
    


  18. F. Lombardini and G. Fornaro. First trials of fourier and adaptive tomo-doppler sar imaging. In Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International, volume 4, pages 2656-2659, July 2005.
    @InProceedings{Lombardini2005a,
    Title = {First trials of fourier and adaptive tomo-doppler sar imaging},
    Author = {Lombardini, F. and Fornaro, G.},
    Booktitle = {Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International},
    Month = jul,
    Pages = {2656--2659},
    Volume = {4},
    Year = {2005},
    Owner = {ofrey},
    Timestamp = {2007.10.11} 
    }
    


  19. C. Lopez-Martinez and E. Pottier. Topography independent InSAR coherence estimation in a multiresolution scheme. In IEEE International Geoscience and Remote Sensing Symposium, IGARSS'05, volume 4, pages 2689-2692, July 2005. Keyword(s): SAR Processing, Coherence, Coherence Estimation, InSAR, Interferometry, SAR Interferometry, Speckle Noise, Wavelet Transform.
    @InProceedings{lopezMartinezPottier2005:Coherence,
    author = {Lopez-Martinez, C. and Pottier, E.},
    booktitle = {IEEE International Geoscience and Remote Sensing Symposium, IGARSS'05},
    title = {Topography independent InSAR coherence estimation in a multiresolution scheme},
    year = {2005},
    month = {July},
    pages = {2689-2692},
    volume = {4},
    keywords = {SAR Processing, Coherence, Coherence Estimation,InSAR, Interferometry, SAR Interferometry, Speckle Noise, Wavelet Transform},
    owner = {ofrey},
    pdf = {../../../docs/lopezMartinezPottier2005.pdf},
    url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=01525620},
    
    }
    


  20. Andreas Muschinski, Fred M. Dickey, and Armin W. Doerry. Possible effects of clear-air refractive-index perturbations on SAR images. In Robert N. Trebits and James L. Kurtz, editors, Proc. of SPIE Vol. 5788, Radar Sensor Technology IX, number 1, pages 25-33, 2005. SPIE. Keyword(s): SAR Processing, Atmospheric Modelling, clear-air radar, thin-lens approximation, clear-air refractive index, sheets, gravity waves, diffraction patterns.
    Abstract: Airborne synthetic aperture radar (SAR) imaging systems have reached a degree of accuracy and sophistication that requires the validity of the free-space approximation for radio-wave propagation to be questioned. Based on the thin-lens approximation, a closed-form model for the focal length of a gravity wave-modulated refractive-index interface in the lower troposphere is developed. The model corroborates the suggestion that mesoscale, quasi-deterministic variations of the clear-air radio refractive-index field can cause diffraction patterns on the ground that are consistent with reflectivity artifacts occasionally seen in SAR images, particularly in those collected at long ranges, short wavelengths, and small grazing angles.

    @InProceedings{MuschinskiDickeyDoerry2005,
    author = {Andreas Muschinski and Fred M. Dickey and Armin W. Doerry},
    title = {Possible effects of clear-air refractive-index perturbations on SAR images},
    booktitle = {Proc. of SPIE Vol. 5788, Radar Sensor Technology IX},
    year = {2005},
    editor = {Robert N. Trebits and James L. Kurtz},
    number = {1},
    pages = {25-33},
    publisher = {SPIE},
    abstract = {Airborne synthetic aperture radar (SAR) imaging systems have reached a degree of accuracy and sophistication that requires the validity of the free-space approximation for radio-wave propagation to be questioned. Based on the thin-lens approximation, a closed-form model for the focal length of a gravity wave-modulated refractive-index interface in the lower troposphere is developed. The model corroborates the suggestion that mesoscale, quasi-deterministic variations of the clear-air radio refractive-index field can cause diffraction patterns on the ground that are consistent with reflectivity artifacts occasionally seen in SAR images, particularly in those collected at long ranges, short wavelengths, and small grazing angles.},
    file = {:MuschinskiDickeyDoerry2005.pdf:PDF},
    keywords = {SAR Processing, Atmospheric Modelling, clear-air radar, thin-lens approximation, clear-air refractive index, sheets, gravity waves, diffraction patterns},
    location = {Orlando, FL, USA},
    owner = {ofrey},
    pdf = {../../../docs/MuschinskiDickeyDoerry2005.pdf},
    url = {http://link.aip.org/link/?PSI/5788/25/1},
    
    }
    


  21. L. Pipia, A. Aguasca, X. Fabregas, J. J. Mallorqui, and C. Lopez-Martinez. Temporal decorrelation in polarimetric differential interferometry using a ground-based SAR sensor. In Proc. IEEE Int. Geoscience and Remote Sensing Symp. IGARSS '05, volume 6, pages 4108-4111, July 2005. Keyword(s): GB-SAR, ground-based SAR, terrestrial SAR, Azimuth, Decorrelation, Temporal Decorrelation, Interferometry, Monitoring, Polarization, Satellites, Semiconductor device measurement, Testing, Urban areas, Vegetation.
    @InProceedings{Pipia2005,
    author = {L. Pipia and A. Aguasca and X. Fabregas and J. J. Mallorqui and C. Lopez-Martinez},
    title = {Temporal decorrelation in polarimetric differential interferometry using a ground-based {SAR} sensor},
    booktitle = {Proc. IEEE Int. Geoscience and Remote Sensing Symp. IGARSS '05},
    year = {2005},
    volume = {6},
    month = jul,
    pages = {4108--4111},
    doi = {10.1109/IGARSS.2005.1525818},
    issn = {2153-6996},
    keywords = {GB-SAR,ground-based SAR, terrestrial SAR,Azimuth, Decorrelation, Temporal Decorrelation, Interferometry, Monitoring, Polarization, Satellites, Semiconductor device measurement, Testing, Urban areas, Vegetation},
    owner = {ofrey},
    
    }
    


  22. P. Prats, A. Reigber, and J. J. Mallorqui. Topography accommodation during motion compensation in interferometric repeat-pass SAR images. In Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International, volume 1, pages 1-4, July 2005. Keyword(s): SAR Processing, Motion Compensation, Topography-Based Motion Compensation, ESAR, L-Band, Airborne SAR, radar imaging, synthetic aperture radar, Topography, German Aerospace Center E-SAR, DLR, SAR data processing, airborne L-band repeat-pass interferometric data, Interferometry, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm, azimuth compression, azimuth coregistration errors, external digital elevation model, DEM, image enhancement, image registration, impulse response degradation, phase artifacts, repeat-pass interferometric SAR systems, Calibration, image registration, repeat-pass interferometry.
    @InProceedings{PratsReigberMallorqui2005a:MoComp,
    Title = {Topography accommodation during motion compensation in interferometric repeat-pass SAR images},
    Author = {Prats, P. and Reigber, A. and Mallorqui, J. J.},
    Booktitle = {Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International},
    Month = jul,
    Pages = {1-4},
    Url = {http://ieeexplore.ieee.org/iel5/10226/32595/01526174.pdf},
    Volume = {1},
    Year = {2005},
    Keywords = {SAR Processing, Motion Compensation,Topography-Based Motion Compensation, ESAR, L-Band, Airborne SAR, radar imaging, synthetic aperture radar, Topography, German Aerospace Center E-SAR, DLR, SAR data processing, airborne L-band repeat-pass interferometric data, Interferometry, Chirp Scaling Algorithm, Extended Chirp Scaling Algorithm, azimuth compression, azimuth coregistration errors, external digital elevation model, DEM, image enhancement, image registration, impulse response degradation, phase artifacts, repeat-pass interferometric SAR systems, Calibration, image registration, repeat-pass interferometry},
    Owner = {ofrey},
    Pdf = {../../../docs/PratsReigberMallorqui2005a.pdf} 
    }
    


  23. Andreas Reigber, Maxim Neumann, Stephane Guillaso, Stefan Sauer, and Laurent Ferro-Famil. Evaluating PolInSAR parameter estimation using tomographic imaging results. In Proc. European Radar Conf., pages 189-192, 2005. Keyword(s): SAR Processing, SAR Tomography, Tomography, forestry, matrix algebra, radar imaging, radar polarimetry, radiowave interferometry, remote sensing by radar, synthetic aperture radar, tomography, vegetation mapping, PolInSAR parameter estimation, canopy, forest height, ground topography estimation, polarimetric SAR interferometry, tomographic imaging results.
    Abstract: This paper concentrates on the forest height and ground topography estimation by means of polarimetric SAR interferometry and tomography. In polarimetric SAR interferometry, one of the most important methods described in literature is the line-fitting approach in the complex unitary circle (S.R. Cloude and K.P. Papathanassiou, 2003). Although it has shown their principal potential, an open issue is still the precise validation of the estimated parameters, as ground-truth collection is an extremely complex task in the case of forest parameters. SAR tomography is an alternative technique, which generates a fully three-dimensional representation of the imaged scene through coherent combination of a greater number of tracks (A. Reigber and A. Moreira, 2000) (S. Guillaso and A. Reigber, 2005). Forest ground and canopy are directly visible in a tomographic image; a tomographic image can therefore be used as an ideal validation base for PolInSAR forest parameter estimation. This paper compares high-resolution polarimetric SAR tomograms with PolInSAR forest height estimations, both derived from the same data set. This allows to identify areas of good applicability, as well as principal deficiencies of the different PolInSAR approaches.

    @InProceedings{reigberNeumannGuillasoSauerFerroFamil05:Tomo,
    Title = {Evaluating {PolInSAR} parameter estimation using tomographic imaging results},
    Author = {Reigber, Andreas and Neumann, Maxim and Guillaso, Stephane and Sauer, Stefan and Ferro-Famil, Laurent},
    Booktitle = {Proc. European Radar Conf.},
    Pages = {189--192},
    Url = {http://ieeexplore.ieee.org/iel5/10685/33742/01605597.pdf},
    Year = {2005},
    Abstract = {This paper concentrates on the forest height and ground topography estimation by means of polarimetric SAR interferometry and tomography. In polarimetric SAR interferometry, one of the most important methods described in literature is the line-fitting approach in the complex unitary circle (S.R. Cloude and K.P. Papathanassiou, 2003). Although it has shown their principal potential, an open issue is still the precise validation of the estimated parameters, as ground-truth collection is an extremely complex task in the case of forest parameters. SAR tomography is an alternative technique, which generates a fully three-dimensional representation of the imaged scene through coherent combination of a greater number of tracks (A. Reigber and A. Moreira, 2000) (S. Guillaso and A. Reigber, 2005). Forest ground and canopy are directly visible in a tomographic image; a tomographic image can therefore be used as an ideal validation base for PolInSAR forest parameter estimation. This paper compares high-resolution polarimetric SAR tomograms with PolInSAR forest height estimations, both derived from the same data set. This allows to identify areas of good applicability, as well as principal deficiencies of the different PolInSAR approaches.},
    Keywords = {SAR Processing, SAR Tomography, Tomography, forestry, matrix algebra, radar imaging, radar polarimetry, radiowave interferometry, remote sensing by radar, synthetic aperture radar, tomography, vegetation mapping, PolInSAR parameter estimation, canopy, forest height, ground topography estimation, polarimetric SAR interferometry, tomographic imaging results},
    Owner = {ofrey},
    Pdf = {../../../docs/reigberNeumannGuillasoSauerFerroFamilTomo05.pdf} 
    }
    


  24. A. Reigber, P. Prats, and J. J. Mallorqui. Refined estimation of time-varying baseline errors in airborne SAR interferometry. In Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International, volume 7, pages 4799-4802, July 2005. Keyword(s): SAR Processing, Airborne SAR, calibration, Interferometry, L-Band, Baseline refinement, calibration, interferometry, InSAR, Motion Compensation, repeat-pass interferometry, Residual Motion Errors, RME, Squinted SAR, Multi-Squint Processing.
    @InProceedings{ReigberPratsMallorqui2005:MoComp,
    Title = {Refined estimation of time-varying baseline errors in airborne SAR interferometry},
    Author = {Reigber, A. and Prats, P. and Mallorqui, J. J.},
    Booktitle = {Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International},
    Month = jul,
    Pages = {4799--4802},
    Url = {http://ieeexplore.ieee.org/iel5/8859/33327/01576708.pdf},
    Volume = {7},
    Year = {2005},
    Keywords = {SAR Processing, Airborne SAR, calibration, Interferometry, L-Band, Baseline refinement, calibration, interferometry,InSAR, Motion Compensation, repeat-pass interferometry, Residual Motion Errors, RME, Squinted SAR, Multi-Squint Processing},
    Owner = {ofrey},
    Pdf = {../../../docs/ReigberPratsMallorqui2005.pdf} 
    }
    


  25. J. Sanz-Marcos, P. Prats, and J. J. Mallorqui. Bistatic fixed-receiver parasitic SAR processor based on the back-propagation algorithm. In Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International, volume 2, pages 1056-1059, July 2005.
    @InProceedings{SanzMarcosPratsMallorqui2005:Bistatic,
    Title = {Bistatic fixed-receiver parasitic SAR processor based on the back-propagation algorithm},
    Author = {Sanz-Marcos, J. and Prats, P. and Mallorqui, J. J.},
    Booktitle = {Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International},
    Doi = {10.1109/IGARSS.2005.1525296},
    Month = jul,
    Pages = {1056--1059},
    Volume = {2},
    Year = {2005},
    Owner = {ofrey},
    Timestamp = {2007.08.14} 
    }
    


  26. F. Serafino, F. Soldovieri, F. Lombardini, and G. Fornaro. Singular value decomposition applied to 4D SAR imaging. In Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International, volume 4, pages 2701-2704, July 2005.
    @InProceedings{Serafino2005,
    Title = {Singular value decomposition applied to 4D SAR imaging},
    Author = {Serafino, F. and Soldovieri, F. and Lombardini, F. and Fornaro, G.},
    Booktitle = {Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International},
    Month = jul,
    Pages = {2701--2704},
    Volume = {4},
    Year = {2005},
    Owner = {ofrey},
    Timestamp = {2007.10.11} 
    }
    


  27. G. Shippey, S. Banks, and J. Pihl. SAS image reconstruction using Fast Polar Back Projection: comparisons with Fast Factored Back Projection and Fourier-domain imaging. In Oceans 2005 - Europe, volume 1, pages 96-101, June 2005. Keyword(s): SAR Processing, Time-Domain Back-Projection, TDBP, Fast-Factorized Back-Projection, FFBP, Fast Polar Back-Projection, FPBP, fast Fourier transforms, image reconstruction, radar imaging, sonar imaging, synthetic aperture radar, synthetic aperture sonar FFBP, FPBP, Fast Factored Back Projection, Fast Polar Back Projection, Fourier-domain imaging, SAS image reconstruction, Synthetic Aperture Radar, Synthetic Aperture Sonar, autopositioning purposes, azimuth sidelobe level, computation time reduction, intermediate physical aperture images, multielement sonar arrays, nonlinear platform trajectories, preset approximation error, review, standard FFT-based method, time-domain methods, ultra-wideband airborne SAR, wide bandwidths, wide swaths.
    Abstract: Fast Polar Back-Projection (FPBP) is a variant of the Fast-Factored Back-Projection (FFBP) algorithm, originally developed for ultra-wideband airborne Synthetic Aperture Radar (SAR), but since applied with success to Synthetic Aperture Sonar (SAS). The paper outlines the FPBP and FFBP algorithms, comparing computation time and memory requirements for the two methods. Processing time comparisons with a standard FFT-based method are also given. Since FFBP and FPBP are both approximation methods, computation time also depends on the preset approximation error, which particularly affects azimuth sidelobe level. The paper provides an opportunity to review speed and accuracy estimates made in previous literature. However reduction in computation time is not the decisive advantage of these time-domain methods. The difference from the FFT-based methods lies in the flexibility with which nonlinear platform trajectories, wide swaths, wide bandwidths, and multielement sonar arrays can be handled. It is also straightforward to obtain a set of intermediate physical aperture images for autopositioning purposes.

    @InProceedings{ShippeyBanksPihl2005:FastBackprojection,
    author = {Shippey, G. and Banks, S. and Pihl, J.},
    booktitle = {Oceans 2005 - Europe},
    title = {SAS image reconstruction using Fast Polar Back Projection: comparisons with Fast Factored Back Projection and Fourier-domain imaging},
    year = {2005},
    month = jun,
    pages = {96-101},
    volume = {1},
    abstract = {Fast Polar Back-Projection (FPBP) is a variant of the Fast-Factored Back-Projection (FFBP) algorithm, originally developed for ultra-wideband airborne Synthetic Aperture Radar (SAR), but since applied with success to Synthetic Aperture Sonar (SAS). The paper outlines the FPBP and FFBP algorithms, comparing computation time and memory requirements for the two methods. Processing time comparisons with a standard FFT-based method are also given. Since FFBP and FPBP are both approximation methods, computation time also depends on the preset approximation error, which particularly affects azimuth sidelobe level. The paper provides an opportunity to review speed and accuracy estimates made in previous literature. However reduction in computation time is not the decisive advantage of these time-domain methods. The difference from the FFT-based methods lies in the flexibility with which nonlinear platform trajectories, wide swaths, wide bandwidths, and multielement sonar arrays can be handled. It is also straightforward to obtain a set of intermediate physical aperture images for autopositioning purposes.},
    doi = {10.1109/OCEANSE.2005.1511691},
    keywords = {SAR Processing, Time-Domain Back-Projection, TDBP, Fast-Factorized Back-Projection, FFBP, Fast Polar Back-Projection,FPBP, fast Fourier transforms, image reconstruction, radar imaging, sonar imaging, synthetic aperture radar, synthetic aperture sonar FFBP, FPBP, Fast Factored Back Projection, Fast Polar Back Projection, Fourier-domain imaging, SAS image reconstruction, Synthetic Aperture Radar, Synthetic Aperture Sonar, autopositioning purposes, azimuth sidelobe level, computation time reduction, intermediate physical aperture images, multielement sonar arrays, nonlinear platform trajectories, preset approximation error, review, standard FFT-based method, time-domain methods, ultra-wideband airborne SAR, wide bandwidths, wide swaths},
    owner = {ofrey},
    pdf = {../../../docs/ShippeyBanksPihl2005.pdf},
    url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1511691&isnumber=32366},
    
    }
    


  28. Zhigang Su, Yingning Peng, and Xiutan Wang. Non-Iterative Imaging Algorithm for CLSAR. In Acoustics, Speech, and Signal Processing, 2005. Proceedings. (ICASSP '05). IEEE International Conference on, volume 2, pages 577-580, 2005. Keyword(s): SAR Processing, Non-Linear Flight Path, SAR Tomography, Curvilinear SAR.
    Abstract: Curvilinear synthetic aperture radar (CLSAR), which aperture is formed via a curvilinear trajectory, is considered as a more practical three-dimensional (3-D) imaging system. The 3-D images obtained by using non-parametricmethods, however, have little practical use because the data collected by CLSAR is sparse in the 3-D frequency space. Some parametric methods have been successfully applied into CLSAR for imaging but have expensive computational cost since they are iteration methods. In this paper, a non-iterative imaging (NII) algorithm is proposed. The new algorithm estimates the range parameters of all scatterers via modern spectrum method, and then using these range estimates and the received data to form the two-dimensional (2-D) data slices, from which the cross-range parameters are estimated. Once the position (range and cross-range) estimates are obtained, the radar cross section (RCS) can be calculated from the data. Simulation results show that the new algorithm can efficiently form the target's 3-D image via CLSAR.

    @InProceedings{suPengWang2005b:NonLinearSARTomo,
    Title = {{Non-Iterative Imaging Algorithm for CLSAR}},
    Author = {Su, Zhigang and Peng, Yingning and Wang, Xiutan},
    Booktitle = {Acoustics, Speech, and Signal Processing, 2005. Proceedings. (ICASSP '05). IEEE International Conference on},
    Pages = {577--580},
    Url = {http://ieeexplore.ieee.org/iel5/9711/30651/01415470.pdf},
    Volume = {2},
    Year = {2005},
    Abstract = {Curvilinear synthetic aperture radar (CLSAR), which aperture is formed via a curvilinear trajectory, is considered as a more practical three-dimensional (3-D) imaging system. The 3-D images obtained by using non-parametricmethods, however, have little practical use because the data collected by CLSAR is sparse in the 3-D frequency space. Some parametric methods have been successfully applied into CLSAR for imaging but have expensive computational cost since they are iteration methods. In this paper, a non-iterative imaging (NII) algorithm is proposed. The new algorithm estimates the range parameters of all scatterers via modern spectrum method, and then using these range estimates and the received data to form the two-dimensional (2-D) data slices, from which the cross-range parameters are estimated. Once the position (range and cross-range) estimates are obtained, the radar cross section (RCS) can be calculated from the data. Simulation results show that the new algorithm can efficiently form the target's 3-D image via CLSAR.},
    ISSN = {1520-6149},
    Keywords = {SAR Processing, Non-Linear Flight Path, SAR Tomography, Curvilinear SAR},
    Owner = {ofrey},
    Pdf = {../../../docs/suPengWang2005b.pdf} 
    }
    


  29. Zhigang Su, Yingning Peng, and Xiutan Wang. Three-dimensional target features extraction in curvilinear SAR with aperture errors. In Communications and Information Technology, 2005. ISCIT 2005. IEEE International Symposium on, volume 2, pages 1227-1230, 2005. Keyword(s): SAR Processing, Non-Linear Flight Path, SAR Tomography, feature extraction, radar imaging, synthetic aperture radar, aperture errors compensation, curvilinear SAR, curvilinear synthetic aperture radar, inverse SAR, phase compensation technique, phase information, range information, reference bins, three-dimensional target features extraction.
    Abstract: In curvilinear synthetic aperture radar (SAR), it is difficult to compensate the curvilinear aperture errors. The algorithm proposed in this paper, based on the phase compensation technique in inverse SAR (ISAR), compensates the aperture errors by using the range and phase information in the reference bins. Consequently, the scatterers' three-dimensional (3-D) features are extracted from the compensated data. Simulation results show that the distribution obtained via the new algorithm, compared with the original distribution, only shifts in three-dimensional position without structure changing. So, the new algorithm is a novel 3-D features extraction algorithm for curvilinear SAR.

    @InProceedings{suPengWang2005:NonLinearSARTomo,
    Title = {Three-dimensional target features extraction in curvilinear SAR with aperture errors},
    Author = {Su, Zhigang and Peng, Yingning and Wang, Xiutan},
    Booktitle = {Communications and Information Technology, 2005. ISCIT 2005. IEEE International Symposium on},
    Pages = {1227--1230},
    Url = {http://ieeexplore.ieee.org/iel5/10481/33237/01567090.pdf},
    Volume = {2},
    Year = {2005},
    Abstract = {In curvilinear synthetic aperture radar (SAR), it is difficult to compensate the curvilinear aperture errors. The algorithm proposed in this paper, based on the phase compensation technique in inverse SAR (ISAR), compensates the aperture errors by using the range and phase information in the reference bins. Consequently, the scatterers' three-dimensional (3-D) features are extracted from the compensated data. Simulation results show that the distribution obtained via the new algorithm, compared with the original distribution, only shifts in three-dimensional position without structure changing. So, the new algorithm is a novel 3-D features extraction algorithm for curvilinear SAR.},
    Keywords = {SAR Processing, Non-Linear Flight Path, SAR Tomography, feature extraction, radar imaging, synthetic aperture radar, aperture errors compensation, curvilinear SAR, curvilinear synthetic aperture radar, inverse SAR, phase compensation technique, phase information, range information, reference bins, three-dimensional target features extraction},
    Pdf = {../../../docs/suPengWang2005.pdf} 
    }
    


  30. Qulin Tan, Zhou Fu, Zhengjun Liu, and Jiping Hu. An experiment for high resolution airborne SAR imaging based on phase gradient autofocus. In Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International, volume 5, pages 3322-3324, July 2005. Keyword(s): SAR Processing, Autofocus, Phase Gradient Autofocus.
    @InProceedings{Tan2005,
    Title = {An experiment for high resolution airborne SAR imaging based on phase gradient autofocus},
    Author = {Qulin Tan and Zhou Fu and Zhengjun Liu and Jiping Hu},
    Booktitle = {Geoscience and Remote Sensing Symposium, 2005. IGARSS '05. Proceedings. 2005 IEEE International},
    Month = jul,
    Pages = {3322--3324},
    Volume = {5},
    Year = {2005},
    Keywords = {SAR Processing, Autofocus, Phase Gradient Autofocus},
    Owner = {ofrey} 
    }
    


  31. G.J. Vigurs, M.S. Wood, and M.L. Jarrett. Non-linear synthetic aperture radar techniques. In Radar Conference, 2005. EURAD 2005. European, pages 13-16, October 2005. Keyword(s): SAR Processing, Non-Linear Flight Path, Simulation, MTI, Moving Target Indication.
    Abstract: The Non-Linear Synthetic Aperture Radar (SAR) technique uses a combination of platform manoeuvre and novel processing to separate the effects of a target's radial velocity and cross-range displacement, giving accurate estimates of both. The technique provides high resolution images free from the image distortion caused in conventional SAR imagery by moving targets, and allows the accurate target location of both stationary and moving objects. The technique also allows the platform to fly a wide range of planned and unplanned manoeuvres, improving platform survivability in potentially hostile environments.

    @InProceedings{vigursWoodJarrett2005:NonLinearSAR,
    Title = {Non-linear synthetic aperture radar techniques},
    Author = {Vigurs, G.J. and Wood, M.S. and Jarrett, M.L.},
    Booktitle = {Radar Conference, 2005. EURAD 2005. European},
    Month = oct,
    Pages = {13--16},
    Url = {http://ieeexplore.ieee.org/iel5/10685/33742/01605552.pdf},
    Year = {2005},
    Abstract = {The Non-Linear Synthetic Aperture Radar (SAR) technique uses a combination of platform manoeuvre and novel processing to separate the effects of a target's radial velocity and cross-range displacement, giving accurate estimates of both. The technique provides high resolution images free from the image distortion caused in conventional SAR imagery by moving targets, and allows the accurate target location of both stationary and moving objects. The technique also allows the platform to fly a wide range of planned and unplanned manoeuvres, improving platform survivability in potentially hostile environments.},
    Keywords = {SAR Processing, Non-Linear Flight Path, Simulation, MTI, Moving Target Indication},
    Owner = {ofrey},
    Pdf = {../../../docs/vigursWoodJarrett2005.pdf} 
    }
    


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This collection of SAR literature is far from being complete.
It is rather a collection of papers which I store in my literature data base. Hence, the list of publications under PUBLICATIONS OF AUTHOR'S NAME should NOT be mistaken for a complete bibliography of that author.




Last modified: Mon Feb 1 16:39:00 2021
Author: Othmar Frey, Earth Observation and Remote Sensing, Institute of Environmental Engineering, Swiss Federal Institute of Technology - ETH Zurich .


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